Switch from jasmine to mocha + expect + lolex

Much of this transformation has been done automatically:
 * add expect import to each file
 * replace `not.to` with `toNot`
 * replace `to[Not]Be{Undefined,Null}` with equivalents
 * replace `jasmine.createSpy(...)` with `except.createSpy`, and `andCallFake`
   with `andCall`

Also:
 * replace `jasmine.createSpyObj` with manual alternatives
 * replace `jasmine.Clock` with `lolex`

spec/mock-request.js

@@ -1,5 +1,6 @@
 "use strict";
 const q = require("q");
+import expect from 'expect';
 
 /**
  * Construct a mock HTTP backend, heavily inspired by Angular.js.