chore: .mjs project cleanup

.eslintignore

@@ -1,4 +1,3 @@
 /es
 /lib
 /node8
-/mjs

.flowconfig

@@ -2,7 +2,6 @@
 <PROJECT_ROOT>/lib/.*
 <PROJECT_ROOT>/es/.*
 <PROJECT_ROOT>/node8/.*
-<PROJECT_ROOT>/mjs/.*
 .*/node_modules/ajv.*
 .*/node_modules/acorn.*
 .*/node_modules/async.*

.gitignore

@@ -42,7 +42,6 @@ node_modules
 /es
 /lib
 /node8
-/mjs
 
 coverage
 .nyc_output

README.md

@@ -24,24 +24,6 @@ OR
 npm install react-relay-network-modern --save
 ```
 
-If using with Webpack 4, make sure that you're equipped to parse .mjs files correctly. (If using Webpack 3, can omit the `module` definition.)
-
-```javascript
-module: {
-  rules: [
-    // See: https://github.com/aws/aws-amplify/issues/686#issuecomment-387710340
-    {
-      test: /\.mjs$/,
-      include: /node_modules\/react-relay-network-modern/,
-      type: 'javascript/auto',
-    },
-  ]
-},
-resolve: {
- extensions: ['.mjs', '.js']
-}
-```
-
 ### What if `regeneratorRuntime is not defined`?
 
 <img width="493" alt="screen shot 2018-02-20 at 20 07 45" src="https://user-images.githubusercontent.com/1946920/36428334-da402a6e-1679-11e8-9897-7e730ab3123e.png">

babel.config.js

@@ -21,21 +21,6 @@ module.exports = {
     es: {
       plugins: ['@babel/plugin-proposal-class-properties'],
     },
-    mjs: {
-      plugins: ['@babel/plugin-proposal-class-properties'],
-      presets: [
-        [
-          '@babel/preset-env',
-          {
-            targets: {
-              browsers: ['last 5 versions', 'ie 9', 'defaults'],
-            },
-            loose: true,
-            modules: false,
-          },
-        ],
-      ],
-    },
     node8: {
       presets: [
         [