Remove unused loaders of webpack (#3495)

config/webpack/loaders/babel.js

 module.exports = {
-  test: /\.js(\.erb)?$/,
+  test: /\.js$/,
   exclude: /node_modules/,
   loader: 'babel-loader',
   options: {

config/webpack/loaders/coffee.js

-module.exports = {
-  test: /\.coffee(\.erb)?$/,
-  loader: 'coffee-loader',
-};

config/webpack/loaders/erb.js

-module.exports = {
-  test: /\.erb$/,
-  enforce: 'pre',
-  exclude: /node_modules/,
-  loader: 'rails-erb-loader',
-  options: {
-    runner: 'bin/rails runner',
-  },
-};

config/webpack/paths.yml

@@ -8,11 +8,7 @@ default: &default
   node_modules: node_modules
   source: app/javascript
   extensions:
-    - .coffee
     - .js
-    - .jsx
-    - .ts
-    - .vue
     - .sass
     - .scss
     - .css

package.json

@@ -39,8 +39,6 @@
     "babel-preset-env": "^1.4.0",
     "babel-preset-react": "^6.24.1",
     "classnames": "^2.2.5",
-    "coffee-loader": "^0.7.3",
-    "coffee-script": "^1.12.6",
     "compression-webpack-plugin": "^0.4.0",
     "css-loader": "^0.28.1",
     "dotenv": "^4.0.0",
@@ -75,7 +73,6 @@
     "precss": "^1.4.0",
     "prop-types": "^15.5.10",
     "punycode": "^2.1.0",
-    "rails-erb-loader": "^5.0.0",
     "rails-ujs": "^5.1.1",
     "react": "^15.5.4",
     "react-addons-perf": "^15.4.2",

yarn.lock

@@ -1636,16 +1636,6 @@ code-point-at@^1.0.0:
   version "1.1.0"
   resolved "https://registry.yarnpkg.com/code-point-at/-/code-point-at-1.1.0.tgz#0d070b4d043a5bea33a2f1a40e2edb3d9a4ccf77"
 
-coffee-loader@^0.7.3:
-  version "0.7.3"
-  resolved "https://registry.yarnpkg.com/coffee-loader/-/coffee-loader-0.7.3.tgz#fadbc6efd6fc7ecc88c5b3046a2c292066bcb54a"
-  dependencies:
-    loader-utils "^1.0.2"
-
-coffee-script@^1.12.6:
-  version "1.12.6"
-  resolved "https://registry.yarnpkg.com/coffee-script/-/coffee-script-1.12.6.tgz#285a3f7115689065064d6bf9ef4572db66695cbf"
-
 collapse-white-space@^1.0.0:
   version "1.0.2"
   resolved "https://registry.yarnpkg.com/collapse-white-space/-/collapse-white-space-1.0.2.tgz#9c463fb9c6d190d2dcae21a356a01bcae9eeef6d"
@@ -3824,7 +3814,7 @@ loader-utils@^0.2.11, loader-utils@^0.2.16, loader-utils@^0.2.7, loader-utils@~0
     json5 "^0.5.0"
     object-assign "^4.0.1"
 
-loader-utils@^1.0.1, loader-utils@^1.0.2, loader-utils@^1.1.0, loader-utils@^1.x:
+loader-utils@^1.0.1, loader-utils@^1.0.2, loader-utils@^1.x:
   version "1.1.0"
   resolved "https://registry.yarnpkg.com/loader-utils/-/loader-utils-1.1.0.tgz#c98aef488bcceda2ffb5e2de646d6a754429f5cd"
   dependencies:
@@ -3887,7 +3877,7 @@ lodash.create@3.1.1:
     lodash._basecreate "^3.0.0"
     lodash._isiterateecall "^3.0.0"
 
-lodash.defaults@^4.0.1, lodash.defaults@^4.2.0:
+lodash.defaults@^4.0.1:
   version "4.2.0"
   resolved "https://registry.yarnpkg.com/lodash.defaults/-/lodash.defaults-4.2.0.tgz#d09178716ffea4dde9e5fb7b37f6f0802274580c"
 
@@ -5362,13 +5352,6 @@ raf@^3.1.0:
   dependencies:
     performance-now "^2.1.0"
 
-rails-erb-loader@^5.0.0:
-  version "5.0.1"
-  resolved "https://registry.yarnpkg.com/rails-erb-loader/-/rails-erb-loader-5.0.1.tgz#d044251851e38259f971105e66b8f43ef3488897"
-  dependencies:
-    loader-utils "^1.1.0"
-    lodash.defaults "^4.2.0"
-
 rails-ujs@^5.1.1:
   version "5.1.1"
   resolved "https://registry.yarnpkg.com/rails-ujs/-/rails-ujs-5.1.1.tgz#0d6e660533141f1ac352830b31c5bfe1b58f79aa"