fix: configure webpack-dotenv to use production env as defaults (#5)

Author: Adam Butterworth

config/webpack.dev.config.js

@@ -126,6 +126,7 @@ module.exports = Merge.smart(commonConfig, {
     }),
     new Dotenv({
       path: path.resolve(PROJECT_ROOT, '.env.development'),
+      systemvars: true,
     }),
     // when the --hot option is not passed in as part of the command
     // the HotModuleReplacementPlugin has to be specified in the Webpack configuration

config/webpack.prod.config.js

@@ -152,6 +152,7 @@ module.exports = Merge.smart(commonConfig, {
     }),
     new Dotenv({
       path: path.resolve(PROJECT_ROOT, '.env'),
+      systemvars: true,
     }),
     new HtmlWebpackNewRelicPlugin({
       // This plugin fixes an issue where the newrelic script will break if