add unpersisted property access

src/config.js

@@ -4,6 +4,7 @@ var CONFIG_FILE = '.remix.config'
 
 function Config (storage) {
   this.items = {}
+  this.unpersistedItems = {}
 
   // load on instantiation
   try {
@@ -44,6 +45,14 @@ function Config (storage) {
       }
     }
   }
+
+  this.getUnpersistedProperty = function (key) {
+    return this.unpersistedItems[key]
+  }
+
+  this.setUnpersistedProperty = function (key, value) {
+    this.unpersistedItems[key] = value
+  }
 }
 
 module.exports = Config