Added duplicatrd packages webpack plugin

.eslintrc

@@ -3,7 +3,6 @@
         "eslint-config-airbnb",
         "plugin:flowtype/recommended",
         "plugin:jest/recommended"
-        
     ],
     "env": {
         "browser": true,

package.json

@@ -76,6 +76,7 @@
         "babel-preset-jest": "^23.2.0",
         "babel-preset-react": "^6.24.1",
         "css-loader": "0.28.11",
+        "duplicate-package-checker-webpack-plugin": "^3.0.0",
         "eslint": "^4",
         "eslint-config-airbnb": "^17.0.0",
         "eslint-import-resolver-babel-plugin-root-import": "^1.1.1",

webpack/config.dev.babel.js

@@ -1,4 +1,4 @@
-
+import DuplicatePackageCheckerPlugin from 'duplicate-package-checker-webpack-plugin';
 import webpack from 'webpack';
 import HtmlWebpackPlugin from 'html-webpack-plugin';
 import MiniCssExtractPlugin from 'mini-css-extract-plugin';
@@ -87,7 +87,7 @@ module.exports = {
             filename: 'index.html',
             inject: true,
         }),
-
+        new DuplicatePackageCheckerPlugin(),
         new webpack.optimize.OccurrenceOrderPlugin(),
         new webpack.NoEmitOnErrorsPlugin(),
         new webpack.HotModuleReplacementPlugin(),

webpack/config.dev.local.babel.js

@@ -1,4 +1,5 @@
 import webpack from 'webpack';
+import DuplicatePackageCheckerPlugin from 'duplicate-package-checker-webpack-plugin';
 import HtmlWebpackPlugin from 'html-webpack-plugin';
 import CopyWebpackPlugin from 'copy-webpack-plugin';
 import MiniCssExtractPlugin from 'mini-css-extract-plugin';
@@ -146,6 +147,7 @@ module.exports = {
         new webpack.NoEmitOnErrorsPlugin(),
         new webpack.HotModuleReplacementPlugin(),
         new webpack.NamedModulesPlugin(),
+        new DuplicatePackageCheckerPlugin(),
 
         new webpack.DefinePlugin({
             LOCAL: JSON.stringify(`http://localhost:${PORT}/`),

yarn.lock

@@ -3122,6 +3122,15 @@ duplexify@^3.4.2, duplexify@^3.5.3:
     readable-stream "^2.0.0"
     stream-shift "^1.0.0"
 
+duplicate-package-checker-webpack-plugin@^3.0.0:
+  version "3.0.0"
+  resolved "https://registry.yarnpkg.com/duplicate-package-checker-webpack-plugin/-/duplicate-package-checker-webpack-plugin-3.0.0.tgz#78bb89e625fa7cf8c2a59c53f62b495fda9ba287"
+  dependencies:
+    chalk "^2.3.0"
+    find-root "^1.0.0"
+    lodash "^4.17.4"
+    semver "^5.4.1"
+
 ecc-jsbn@~0.1.1:
   version "0.1.1"
   resolved "https://registry.yarnpkg.com/ecc-jsbn/-/ecc-jsbn-0.1.1.tgz#0fc73a9ed5f0d53c38193398523ef7e543777505"
@@ -3903,6 +3912,10 @@ find-cache-dir@^1.0.0:
     make-dir "^1.0.0"
     pkg-dir "^2.0.0"
 
+find-root@^1.0.0:
+  version "1.1.0"
+  resolved "https://registry.yarnpkg.com/find-root/-/find-root-1.1.0.tgz#abcfc8ba76f708c42a97b3d685b7e9450bfb9ce4"
+
 find-up@^1.0.0:
   version "1.1.2"
   resolved "https://registry.yarnpkg.com/find-up/-/find-up-1.1.2.tgz#6b2e9822b1a2ce0a60ab64d610eccad53cb24d0f"