docs(TestInjector): reenable jsdoc comment for exported inject function

This was disabled due to a bug in dgeni. See angular#949

Author: petebacondarwin

modules/angular2/src/test_lib/test_injector.js

@@ -66,7 +66,7 @@ export function createTestInjector(bindings: List) {
  return rootInjector.createChild(ListWrapper.concat(_getAppBindings(), bindings));
 }
 
-/*
+/**
  * Allows injecting dependencies in `beforeEach()` and `it()`.
  *
  * Example: