Enable compression on webpack-dev-server (facebook#966) (facebook#968)

Author: frontsideair

Diff for: packages/react-scripts/scripts/start.js

@@ -195,6 +195,8 @@ function addMiddleware(devServer) {
 
 function runDevServer(host, port, protocol) {
   var devServer = new WebpackDevServer(compiler, {
+    // Enable gzip compression of generated files.
+    compress: true,
     // Silence WebpackDevServer's own logs since they're generally not useful.
     // It will still show compile warnings and errors with this setting.
     clientLogLevel: 'none',