diff --git a/reactjs-intro/package-lock.json b/reactjs-intro/package-lock.json
index e2e4f71..48c44d5 100644
--- a/reactjs-intro/package-lock.json
+++ b/reactjs-intro/package-lock.json
@@ -1222,6 +1222,13 @@
         "qs": "6.5.1",
         "raw-body": "2.3.2",
         "type-is": "1.6.15"
+      },
+      "dependencies": {
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+          "resolved": "https://registry.npmjs.org/qs/-/qs-6.5.1.tgz",
+          "integrity": "sha512-eRzhrN1WSINYCDCbrz796z37LOe3m5tmW7RQf6oBntukAG1nmovJvhnwHHRMAfeoItc1m2Hk02WER2aQ/iqs+A=="
+        }
       }
     },
     "bonjour": {
@@ -3076,6 +3083,13 @@
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       "requires": {
         "merge": "1.2.0"
+      },
+      "dependencies": {
+        "merge": {
+          "version": "1.2.0",
+          "resolved": "https://registry.npmjs.org/merge/-/merge-1.2.0.tgz",
+          "integrity": "sha512-3GGUnRRpmQMsRpuMbW26z/raenVYeYXcGR1qBGvlHmPq5jaXqL1Zqgdh/0bRw+mTE6F2oTjCj8Tb/wUOy61/CA=="
+        }
       }
     },
     "execa": {
@@ -3119,49 +3133,54 @@
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       "resolved": "https://registry.npmjs.org/express/-/express-4.16.2.tgz",
-      "integrity": "sha1-41xt/i1kt9ygpc1PIXgb4ymeB2w=",
+      "integrity": "sha512-4mc9RUEAUpPMFR6gpXcnPt0/q2Zil35FTUr07ixWYX90RmUKL3jUbvTvJzkc/uL3r+A7kuWSiIqOyVUSWoZXWQ==",
       "requires": {
-        "accepts": "1.3.4",
+        "accepts": "~1.3.4",
         "array-flatten": "1.1.1",
         "body-parser": "1.18.2",
         "content-disposition": "0.5.2",
-        "content-type": "1.0.4",
+        "content-type": "~1.0.4",
         "cookie": "0.3.1",
         "cookie-signature": "1.0.6",
         "debug": "2.6.9",
-        "depd": "1.1.1",
-        "encodeurl": "1.0.1",
-        "escape-html": "1.0.3",
-        "etag": "1.8.1",
+        "depd": "~1.1.1",
+        "encodeurl": "~1.0.1",
+        "escape-html": "~1.0.3",
+        "etag": "~1.8.1",
         "finalhandler": "1.1.0",
         "fresh": "0.5.2",
         "merge-descriptors": "1.0.1",
-        "methods": "1.1.2",
-        "on-finished": "2.3.0",
-        "parseurl": "1.3.2",
+        "methods": "~1.1.2",
+        "on-finished": "~2.3.0",
+        "parseurl": "~1.3.2",
         "path-to-regexp": "0.1.7",
-        "proxy-addr": "2.0.2",
+        "proxy-addr": "~2.0.2",
         "qs": "6.5.1",
-        "range-parser": "1.2.0",
+        "range-parser": "~1.2.0",
         "safe-buffer": "5.1.1",
         "send": "0.16.1",
         "serve-static": "1.13.1",
         "setprototypeof": "1.1.0",
-        "statuses": "1.3.1",
-        "type-is": "1.6.15",
+        "statuses": "~1.3.1",
+        "type-is": "~1.6.15",
         "utils-merge": "1.0.1",
-        "vary": "1.1.2"
+        "vary": "~1.1.2"
       },
       "dependencies": {
         "array-flatten": {
           "version": "1.1.1",
           "resolved": "https://registry.npmjs.org/array-flatten/-/array-flatten-1.1.1.tgz",
-          "integrity": "sha1-ml9pkFGx5wczKPKgCJaLZOopVdI="
+          "integrity": "sha512-PCVAQswWemu6UdxsDFFX/+gVeYqKAod3D3UVm91jHwynguOwAvYPhx8nNlM++NqRcK6CxxpUafjmhIdKiHibqg=="
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           "version": "0.1.7",
           "resolved": "https://registry.npmjs.org/path-to-regexp/-/path-to-regexp-0.1.7.tgz",
-          "integrity": "sha1-32BBeABfUi8V60SQ5yR6G/qmf4w="
+          "integrity": "sha512-5DFkuoqlv1uYQKxy8omFBeJPQcdoE07Kv2sferDCrAq1ohOU+MSDswDIbnx3YAM60qIOnYa53wBhXW0EbMonrQ=="
+        },
+        "qs": {
+          "version": "6.5.1",
+          "resolved": "https://registry.npmjs.org/qs/-/qs-6.5.1.tgz",
+          "integrity": "sha512-eRzhrN1WSINYCDCbrz796z37LOe3m5tmW7RQf6oBntukAG1nmovJvhnwHHRMAfeoItc1m2Hk02WER2aQ/iqs+A=="
         }
       }
     },
@@ -3448,7 +3467,8 @@
         },
         "ansi-regex": {
           "version": "2.1.1",
-          "bundled": true
+          "bundled": true,
+          "optional": true
         },
         "aproba": {
           "version": "1.1.1",
@@ -3491,7 +3511,8 @@
         },
         "balanced-match": {
           "version": "0.4.2",
-          "bundled": true
+          "bundled": true,
+          "optional": true
         },
         "bcrypt-pbkdf": {
           "version": "1.0.1",
@@ -3504,6 +3525,7 @@
         "block-stream": {
           "version": "0.0.9",
           "bundled": true,
+          "optional": true,
           "requires": {
             "inherits": "2.0.3"
           }
@@ -3511,6 +3533,7 @@
         "boom": {
           "version": "2.10.1",
           "bundled": true,
+          "optional": true,
           "requires": {
             "hoek": "2.16.3"
           }
@@ -3518,6 +3541,7 @@
         "brace-expansion": {
           "version": "1.1.7",
           "bundled": true,
+          "optional": true,
           "requires": {
             "balanced-match": "0.4.2",
             "concat-map": "0.0.1"
@@ -3525,7 +3549,8 @@
         },
         "buffer-shims": {
           "version": "1.0.0",
-          "bundled": true
+          "bundled": true,
+          "optional": true
         },
         "caseless": {
           "version": "0.12.0",
@@ -3539,26 +3564,31 @@
         },
         "code-point-at": {
           "version": "1.1.0",
-          "bundled": true
+          "bundled": true,
+          "optional": true
         },
         "combined-stream": {
           "version": "1.0.5",
           "bundled": true,
+          "optional": true,
           "requires": {
             "delayed-stream": "1.0.0"
           }
         },
         "concat-map": {
           "version": "0.0.1",
-          "bundled": true
+          "bundled": true,
+          "optional": true
         },
         "console-control-strings": {
           "version": "1.1.0",
-          "bundled": true
+          "bundled": true,
+          "optional": true
         },
         "core-util-is": {
           "version": "1.0.2",
-          "bundled": true
+          "bundled": true,
+          "optional": true
         },
         "cryptiles": {
           "version": "2.0.5",
@@ -3598,7 +3628,8 @@
         },
         "delayed-stream": {
           "version": "1.0.0",
-          "bundled": true
+          "bundled": true,
+          "optional": true
         },
         "delegates": {
           "version": "1.0.0",
@@ -3620,7 +3651,8 @@
         },
         "extsprintf": {
           "version": "1.0.2",
-          "bundled": true
+          "bundled": true,
+          "optional": true
         },
         "forever-agent": {
           "version": "0.6.1",
@@ -3639,11 +3671,13 @@
         },
         "fs.realpath": {
           "version": "1.0.0",
-          "bundled": true
+          "bundled": true,
+          "optional": true
         },
         "fstream": {
           "version": "1.0.11",
           "bundled": true,
+          "optional": true,
           "requires": {
             "graceful-fs": "4.1.11",
             "inherits": "2.0.3",
@@ -3694,6 +3728,7 @@
         "glob": {
           "version": "7.1.2",
           "bundled": true,
+          "optional": true,
           "requires": {
             "fs.realpath": "1.0.0",
             "inflight": "1.0.6",
@@ -3705,7 +3740,8 @@
         },
         "graceful-fs": {
           "version": "4.1.11",
-          "bundled": true
+          "bundled": true,
+          "optional": true
         },
         "har-schema": {
           "version": "1.0.5",
@@ -3739,7 +3775,8 @@
         },
         "hoek": {
           "version": "2.16.3",
-          "bundled": true
+          "bundled": true,
+          "optional": true
         },
         "http-signature": {
           "version": "1.1.1",
@@ -3754,6 +3791,7 @@
         "inflight": {
           "version": "1.0.6",
           "bundled": true,
+          "optional": true,
           "requires": {
             "once": "1.4.0",
             "wrappy": "1.0.2"
@@ -3761,7 +3799,8 @@
         },
         "inherits": {
           "version": "2.0.3",
-          "bundled": true
+          "bundled": true,
+          "optional": true
         },
         "ini": {
           "version": "1.3.4",
@@ -3771,6 +3810,7 @@
         "is-fullwidth-code-point": {
           "version": "1.0.0",
           "bundled": true,
+          "optional": true,
           "requires": {
             "number-is-nan": "1.0.1"
           }
@@ -3782,7 +3822,8 @@
         },
         "isarray": {
           "version": "1.0.0",
-          "bundled": true
+          "bundled": true,
+          "optional": true
         },
         "isstream": {
           "version": "0.1.2",
@@ -3845,11 +3886,13 @@
         },
         "mime-db": {
           "version": "1.27.0",
-          "bundled": true
+          "bundled": true,
+          "optional": true
         },
         "mime-types": {
           "version": "2.1.15",
           "bundled": true,
+          "optional": true,
           "requires": {
             "mime-db": "1.27.0"
           }
@@ -3857,17 +3900,20 @@
         "minimatch": {
           "version": "3.0.4",
           "bundled": true,
+          "optional": true,
           "requires": {
             "brace-expansion": "1.1.7"
           }
         },
         "minimist": {
           "version": "0.0.8",
-          "bundled": true
+          "bundled": true,
+          "optional": true
         },
         "mkdirp": {
           "version": "0.5.1",
           "bundled": true,
+          "optional": true,
           "requires": {
             "minimist": "0.0.8"
           }
@@ -3915,7 +3961,8 @@
         },
         "number-is-nan": {
           "version": "1.0.1",
-          "bundled": true
+          "bundled": true,
+          "optional": true
         },
         "oauth-sign": {
           "version": "0.8.2",
@@ -3930,6 +3977,7 @@
         "once": {
           "version": "1.4.0",
           "bundled": true,
+          "optional": true,
           "requires": {
             "wrappy": "1.0.2"
           }
@@ -3955,7 +4003,8 @@
         },
         "path-is-absolute": {
           "version": "1.0.1",
-          "bundled": true
+          "bundled": true,
+          "optional": true
         },
         "performance-now": {
           "version": "0.2.0",
@@ -3964,15 +4013,11 @@
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         "process-nextick-args": {
           "version": "1.0.7",
-          "bundled": true
-        },
-        "punycode": {
-          "version": "1.4.1",
           "bundled": true,
           "optional": true
         },
-        "qs": {
-          "version": "6.4.0",
+        "punycode": {
+          "version": "1.4.1",
           "bundled": true,
           "optional": true
         },
@@ -3997,6 +4042,7 @@
         "readable-stream": {
           "version": "2.2.9",
           "bundled": true,
+          "optional": true,
           "requires": {
             "buffer-shims": "1.0.0",
             "core-util-is": "1.0.2",
@@ -4039,13 +4085,15 @@
         "rimraf": {
           "version": "2.6.1",
           "bundled": true,
+          "optional": true,
           "requires": {
             "glob": "7.1.2"
           }
         },
         "safe-buffer": {
           "version": "5.0.1",
-          "bundled": true
+          "bundled": true,
+          "optional": true
         },
         "semver": {
           "version": "5.3.0",
@@ -4096,6 +4144,7 @@
         "string-width": {
           "version": "1.0.2",
           "bundled": true,
+          "optional": true,
           "requires": {
             "code-point-at": "1.1.0",
             "is-fullwidth-code-point": "1.0.0",
@@ -4105,6 +4154,7 @@
         "string_decoder": {
           "version": "1.0.1",
           "bundled": true,
+          "optional": true,
           "requires": {
             "safe-buffer": "5.0.1"
           }
@@ -4117,6 +4167,7 @@
         "strip-ansi": {
           "version": "3.0.1",
           "bundled": true,
+          "optional": true,
           "requires": {
             "ansi-regex": "2.1.1"
           }
@@ -4129,6 +4180,7 @@
         "tar": {
           "version": "2.2.1",
           "bundled": true,
+          "optional": true,
           "requires": {
             "block-stream": "0.0.9",
             "fstream": "1.0.11",
@@ -4178,7 +4230,8 @@
         },
         "util-deprecate": {
           "version": "1.0.2",
-          "bundled": true
+          "bundled": true,
+          "optional": true
         },
         "uuid": {
           "version": "3.0.1",
@@ -4203,7 +4256,8 @@
         },
         "wrappy": {
           "version": "1.0.2",
-          "bundled": true
+          "bundled": true,
+          "optional": true
         }
       }
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@@ -5992,11 +6046,6 @@
         }
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-    "merge": {
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-      "resolved": "https://registry.npmjs.org/merge/-/merge-1.2.0.tgz",
-      "integrity": "sha1-dTHjnUlJwoGma4xabgJl6LBYlNo="
-    },
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       "version": "1.0.1",
       "resolved": "https://registry.npmjs.org/merge-descriptors/-/merge-descriptors-1.0.1.tgz",
@@ -7904,9 +7953,10 @@
       "integrity": "sha1-fjL3W0E4EpHQRhHxvxQQmsAGUdc="
     },
     "qs": {
-      "version": "6.5.1",
-      "resolved": "https://registry.npmjs.org/qs/-/qs-6.5.1.tgz",
-      "integrity": "sha512-eRzhrN1WSINYCDCbrz796z37LOe3m5tmW7RQf6oBntukAG1nmovJvhnwHHRMAfeoItc1m2Hk02WER2aQ/iqs+A=="
+      "version": "6.4.0",
+      "resolved": "https://registry.npmjs.org/qs/-/qs-6.4.0.tgz",
+      "integrity": "sha512-Qs6dfgR5OksK/PSxl1kGxiZgEQe8RqJMB9wZqVlKQfU+zzV+HY77pWJnoJENACKDQByWdpr8ZPIh1TBi4lpiSQ==",
+      "optional": true
     },
     "query-string": {
       "version": "4.3.4",
@@ -8441,6 +8491,13 @@
         "tough-cookie": "2.3.3",
         "tunnel-agent": "0.6.0",
         "uuid": "3.1.0"
+      },
+      "dependencies": {
+        "qs": {
+          "version": "6.5.1",
+          "resolved": "https://registry.npmjs.org/qs/-/qs-6.5.1.tgz",
+          "integrity": "sha512-eRzhrN1WSINYCDCbrz796z37LOe3m5tmW7RQf6oBntukAG1nmovJvhnwHHRMAfeoItc1m2Hk02WER2aQ/iqs+A=="
+        }
       }
     },
     "require-directory": {