chore: Remove env variables in webpack bundle (#1353)

* chore: Remove env variables in webpack bundle

* remove unused globals

* refactor: consolidate window.env calls to single file

* fix: Slack client side integration auth

* fix: developers url

webpack.config.dev.js

@@ -1,24 +1,23 @@
 /* eslint-disable */
-const webpack = require('webpack');
-const HtmlWebpackPlugin = require('html-webpack-plugin');
-const commonWebpackConfig = require('./webpack.config');
+const webpack = require("webpack");
+const commonWebpackConfig = require("./webpack.config");
 
 const developmentWebpackConfig = Object.assign(commonWebpackConfig, {
   cache: true,
-  devtool: 'eval-source-map',
+  devtool: "eval-source-map",
   entry: [
-    'babel-polyfill',
-    'babel-regenerator-runtime',
-    'webpack-hot-middleware/client',
-    './app/index',
+    "babel-polyfill",
+    "babel-regenerator-runtime",
+    "webpack-hot-middleware/client",
+    "./app/index",
   ],
 });
 
 developmentWebpackConfig.plugins = [
   ...developmentWebpackConfig.plugins,
   new webpack.HotModuleReplacementPlugin(),
-  new HtmlWebpackPlugin({
-    title: 'Outline',
+  new webpack.DefinePlugin({
+    "process.env.NODE_ENV": JSON.stringify("development"),
   }),
 ];