Remove webpack-dev-server

I never got around to setting this up, so lets remove it.

package.json

@@ -16,7 +16,6 @@
   "scripts": {
     "lint": "eslint chrome-ext",
     "start": "webpack -w",
-    "start:dev": "NODE_PATH=. NODE_ENV='development' webpack-dev-server --content-base chrome-ext/build",
     "test": "jest",
     "coveralls": "NODE_PATH=. node_modules/.bin/jest && cat ./coverage/lcov.info | ./node_modules/coveralls/bin/coveralls.js",
     "build": "webpack -p",
@@ -53,7 +52,6 @@
     "sass-loader": "8.0.2",
     "style-loader": "1.1.3",
     "webpack": "4.42.1",
-    "webpack-cli": "3.3.11",
-    "webpack-dev-server": "3.10.3"
+    "webpack-cli": "3.3.11"
   }
 }

webpack.config.js

@@ -9,10 +9,6 @@ module.exports = {
 
   devtool: 'cheap-source-map',
 
-  devServer: {
-    contentBase: `${__dirname}/chrome-ext/build`,
-  },
-
   entry: {
     bundle: './chrome-ext/frontend/devtools.js',
     installHook: './chrome-ext/backend/installHook.js',