Fixed reference in test and add comments based on contribution

redux-immutable/redux-immutable-test.ts

@@ -1,3 +1,5 @@
+/// <reference path="redux-immutable.d.ts" />
+
 import { combineReducers } from 'redux-immutable';
 import { routerReducer } from 'react-router-redux';
 

redux-immutable/redux-immutable.d.ts

@@ -1,3 +1,8 @@
+// Type definitions for redux-immutable v3.0.5
+// Project: https://github.com/gajus/redux-immutable
+// Definitions by: Pedro Pereira <https://github.com/oizie>
+// Definitions: https://github.com/borisyankov/DefinitelyTyped
+
 declare module "redux-immutable" {
     export function combineReducers(reducers : Object): Object;
 }