chore(typings): remove traceur-runtime.d.ts

fixes #4297

Closes #4415

modules/angular2/test/http/backends/jsonp_backend_spec.ts

@@ -30,11 +30,8 @@ var unused: Response;
 
 class MockBrowserJsonp extends BrowserJsonp {
   src: string;
-  callbacks: Map<string, (data: any) => any>;
-  constructor() {
-    super();
-    this.callbacks = new Map();
-  }
+  callbacks = new Map<string, (data: any) => any>();
+  constructor() { super(); }
 
   addEventListener(type: string, cb: (data: any) => any) { this.callbacks.set(type, cb); }
 

modules/angular2/test/http/backends/xhr_backend_spec.ts

@@ -38,7 +38,7 @@ class MockBrowserXHR extends BrowserXhr {
   response: any;
   responseText: string;
   setRequestHeader: any;
-  callbacks: Map<string, Function>;
+  callbacks = new Map<string, Function>();
   status: number;
   constructor() {
     super();
@@ -47,7 +47,6 @@ class MockBrowserXHR extends BrowserXhr {
     this.send = sendSpy = spy.spy('send');
     this.open = openSpy = spy.spy('open');
     this.setRequestHeader = setRequestHeaderSpy = spy.spy('setRequestHeader');
-    this.callbacks = new Map();
   }
 
   setStatusCode(status) { this.status = status; }