Added iredmail class and used-quota model

config/index.js

@@ -1,6 +1,14 @@
-const common = require('./env/common')
+// Attempt to include a common.js config file, if it exists.
+let common
+try {
+  common = require('./env/common')
+} catch (err) {}
 
+// Default to development environment.
 const env = process.env.NODE_ENV || 'development'
+
+// Load the config object for the selected environment.
 const config = require(`./env/${env}`)
 
+// Merge into a single object and export.
 module.exports = Object.assign({}, common, config)