Convert mocking from proxyquire to mockable-imports

Convert proxyquire mocking of several CoffeeScript modules.

src/annotator/plugin/test/cross-frame-test.coffee

-proxyquire = require('proxyquire')
-
 Plugin = require('../../plugin')
-CrossFrame = null
+CrossFrame = require('../cross-frame')
 
 describe 'CrossFrame', ->
   fakeDiscovery = null
@@ -41,16 +39,16 @@ describe 'CrossFrame', ->
     proxyDiscovery = sandbox.stub().returns(fakeDiscovery)
     proxyBridge = sandbox.stub().returns(fakeBridge)
 
-    CrossFrame = proxyquire('../cross-frame', {
+    CrossFrame.$imports.$mock({
       '../plugin': Plugin,
       '../annotation-sync': proxyAnnotationSync,
       '../../shared/bridge': proxyBridge,
       '../../shared/discovery': proxyDiscovery
     })
 
-
   afterEach ->
     sandbox.restore()
+    CrossFrame.$imports.$restore()
 
   describe 'CrossFrame constructor', ->
     it 'instantiates the Discovery component', ->

src/annotator/test/host-test.coffee

-proxyquire = require('proxyquire')
-Host = proxyquire('../host', {})
+Host = require('../host')
 
 describe 'Host', ->
   sandbox = sinon.sandbox.create()

src/annotator/test/integration/multi-frame-test.js

 'use strict';
 
-const proxyquire = require('proxyquire');
 const isLoaded = require('../../util/frame-util').isLoaded;
 
 const FRAME_DEBOUNCE_WAIT = require('../../frame-observer').DEBOUNCE_WAIT + 10;
+const CrossFrame = require('../../plugin/cross-frame');
 
 describe('CrossFrame multi-frame scenario', function() {
   let fakeAnnotationSync;
@@ -30,7 +30,7 @@ describe('CrossFrame multi-frame scenario', function() {
     proxyAnnotationSync = sandbox.stub().returns(fakeAnnotationSync);
     proxyBridge = sandbox.stub().returns(fakeBridge);
 
-    const CrossFrame = proxyquire('../../plugin/cross-frame', {
+    CrossFrame.$imports.$mock({
       '../annotation-sync': proxyAnnotationSync,
       '../../shared/bridge': proxyBridge,
     });
@@ -53,6 +53,8 @@ describe('CrossFrame multi-frame scenario', function() {
     sandbox.restore();
     crossFrame.destroy();
     container.parentNode.removeChild(container);
+
+    CrossFrame.$imports.$restore();
   });
 
   it('detects frames on page', function() {

src/annotator/test/sidebar-test.coffee

 events = require('../../shared/bridge-events')
 
-proxyquire = require('proxyquire')
-
-rafStub = (fn) ->
-  fn()
-
-Sidebar = proxyquire('../sidebar', { raf: rafStub })
+Sidebar = require('../sidebar')
 
 DEFAULT_WIDTH = 350
 DEFAULT_HEIGHT = 600
@@ -17,6 +12,14 @@ describe 'Sidebar', ->
   fakeCrossFrame = null
   sidebarConfig = {pluginClasses: {}}
 
+  before ->
+    rafStub = (fn) ->
+      fn()
+    Sidebar.$imports.$mock({ raf: rafStub })
+
+  after ->
+    Sidebar.$imports.$restore()
+
   createSidebar = (config={}) ->
     config = Object.assign({}, sidebarConfig, config)
     element = document.createElement('div')