Support .travis.yml files in the .github directory

[native-api]

Duplicate of

Allow repositories to specify where `.travis.yml` should be found

I’d like to keep repository free from CI configuration noise. e.g. Appveyor CI allows to provide an URL to YAML config on project settings in Appveyor GUI. It’s great also for other reason, as that way I can easily share common config among projects that require same setup. Is there any way to achieve that with Travis CI? If not, is it somewhere on a roadmap?