Update karma-babel-preprocessor to the latest version 🚀 (#1440)

* chore(package): update karma-babel-preprocessor to version 7.0.0

Author: greenkeeper[bot]

package.json

@@ -23,6 +23,7 @@
     "file-saver": "1.3.3"
   },
   "devDependencies": {
+    "babel-core": "6.26.0",
     "babel-preset-es2015": "6.24.1",
     "babel-preset-es2015-rollup": "3.0.0",
     "codeclimate-test-reporter": "^0.5.0",
@@ -32,7 +33,7 @@
     "js-yaml": "3.10.0",
     "jsdoc": "3.5.5",
     "karma": "2.0.0",
-    "karma-babel-preprocessor": "6.0.1",
+    "karma-babel-preprocessor": "7.0.0",
     "karma-chrome-launcher": "2.2.0",
     "karma-coverage": "1.1.1",
     "karma-firefox-launcher": "1.1.0",