chore(travis): enable the typescript@next build

Fixes #7050

modules/angular2/src/http/backends/mock_backend.ts

@@ -35,7 +35,7 @@ export class MockConnection implements Connection {
   response: ReplaySubject<Response>;
 
   constructor(req: Request) {
-    this.response = take.call(new ReplaySubject(1), 1);
+    this.response = <any>take.call(new ReplaySubject(1), 1);
     this.readyState = ReadyState.Open;
     this.request = req;
   }

modules/angular2/src/platform/server/parse5_adapter.ts

@@ -159,7 +159,7 @@ export class Parse5DomAdapter extends DomAdapter {
     var evt = <Event>{
       type: eventType,
       defaultPrevented: false,
-      preventDefault: () => { evt.defaultPrevented = true; }
+      preventDefault: () => { (<any>evt).defaultPrevented = true; }
     };
     return evt;
   }