Enabled fetch-mock with tests.

This patch adds the fetch-mock library, demonstrating how it may be
used to properly mock out API calls. An important change that was
made was the way that 'isomorphic-fetch' was included. Since
fetch-mock makes the assumption that only the window.fetch object
should be overridden, we cannot invoke it via a variable. Instead,
I've simply imported the library, which during import will override
global.fetch if necessary.

Change-Id: Ibd88b61595b4492f375294a8a08031a1a001a10c

package.json

@@ -36,6 +36,7 @@
     "babel-register": "^6.9.0",
     "eslint": "^2.4.0",
     "eslint-config-openstack": "2.0.0",
+    "fetch-mock": "^5.0.5",
     "istanbul": "^1.0.0-alpha.2",
     "jasmine": "^2.4.1",
     "karma": "^1.1.1",

src/index.js

@@ -1,14 +1,13 @@
 import 'babel-polyfill';
-import fetch from 'isomorphic-fetch';
+import 'isomorphic-fetch';
 import log from 'loglevel';
 
 log.setLevel('INFO');
 
 export default class Test {
-  getUrl(url) {
+  getUrl (url) {
     return fetch(url)
       .then((response) => {
-        log.info(response.status);
         return response;
       });
   }

test/unit/indexTest.js

@@ -1,8 +1,32 @@
 import Test from "../../src/index.js";
 
+const FetchMock = require('fetch-mock');
+
 describe("Simple test", () => {
+
+  afterEach(() => {
+    FetchMock.reset();
+  });
+
   it("should export a class", () => {
     let t = new Test();
     expect(t).toBeDefined();
   });
+
+  it("should retrieve URL's", (done) => {
+    FetchMock.get("http://example.com/", {
+      status: 200,
+      body: "This is a test"
+    });
+
+    let t = new Test();
+    t.getUrl("http://example.com/")
+      .then((response) => {
+        return response.text();
+      })
+      .then((body) => {
+        expect(body).toEqual("This is a test");
+        done();
+      });
+  });
 });