[webapi][xwalk-3001] Remove test suite of HTML Templates

- There is no feature requirement in this JIRA system for the HTML Templates, so only check this feature by usecase https://github.com/crosswalk-project/demo-express/tree/master/samples/HTMLTemplate
Merge pull request #1258 from haoxli/webapi/xwalk-3001

[webapi][xwalk-3001] Remove test suite of HTML Templates