Update package version constraints (#15)

Updates composer version constraints. There is no reason to specify the upper limit of `testbench` and `illuminate/*`

Author: sixlive

composer.json

@@ -21,19 +21,19 @@
         }
     ],
     "require": {
-        "php": "^7.1|^7.2",
+        "php": "^7.1|7.2",
         "honeybadger-io/honeybadger-php": "^1.2",
-        "illuminate/console": "^5.5|^5.6",
-        "illuminate/support": "^5.5|^5.6",
-        "sixlive/dotenv-editor": "^1.1"
+        "sixlive/dotenv-editor": "^1.1",
+        "illuminate/console": "^5.5",
+        "illuminate/support": "^5.5"
     },
     "require-dev": {
         "friendsofphp/php-cs-fixer": "^2.10",
         "larapack/dd": "^1.0",
         "mockery/mockery": "^1.1",
-        "orchestra/testbench": "^3.5|^3.6|^3.7",
-        "phpunit/phpunit": "^6.0|^7.0",
-        "sempro/phpunit-pretty-print": "^1.0"
+        "sempro/phpunit-pretty-print": "^1.0",
+        "orchestra/testbench": "^3.5",
+        "phpunit/phpunit": "^6.0|^7.0"
     },
     "autoload": {
         "psr-4": {