Add config file for envs

config/config.js

@@ -0,0 +1,11 @@
+const env = process.env.NODE_ENV || 'development'
+
+const config = {
+  common: {
+    port: process.env.PORT || 5000
+  },
+  development: {},
+  production: {}
+}
+
+export default Object.assign({}, config.common, config[env])