Enable production optimizations when compiling in production (#2234)

lib/install/loaders/elm.js

@@ -1,18 +1,21 @@
 const { resolve } = require('path')
 
 const isProduction = process.env.NODE_ENV === 'production'
+const isDevelopment = process.env.NODE_ENV === 'development'
 const elmSource = resolve(process.cwd())
 const elmBinary = `${elmSource}/node_modules/.bin/elm`
 
-const elmDefaultOptions = { cwd: elmSource, pathToElm: elmBinary }
-const developmentOptions = Object.assign({}, elmDefaultOptions, {
-  verbose: true,
-  debug: true
-})
+const options = { 
+  cwd: elmSource, 
+  pathToElm: elmBinary, 
+  optimize: isProduction, 
+  verbose: isDevelopment, 
+  debug: isDevelopment  
+}
 
 const elmWebpackLoader = {
   loader: 'elm-webpack-loader',
-  options: isProduction ? elmDefaultOptions : developmentOptions
+  options: options
 }
 
 module.exports = {