don't waste time gzip'ing contents of babel-loader's cache

lib/pipeline/webpack.config.js

@@ -103,6 +103,7 @@ const base = {
         exclude: /(node_modules|bower_components|\.embark[\\/]versions)/,
         options: {
           cacheDirectory: true,
+          cacheCompression: false,
           customize: path.join(__dirname, 'babel-loader-overrides.js'),
           plugins: [
             [