chore(build): add check for merge conflicts, ddescribe, and iit

FYI, the build currently fails due to [test/ng/directive/inputSpec.js](https://github.com/angular/angular.js/blob/master/test/ng/directive/inputSpec.js#L993):

```
Running "ddescribe-iit:files" (ddescribe-iit) task
>> test/ng/directive/inputSpec.js has `xit` at line 993
```