Support additional CI services

[dylans]

We should investigate support for some additional CI platforms:

• AppVeyor
• CircleCI (Add CircleCI reporter or support #665)
• Semaphore

[ervinb]

@dylans Let me know if you need a hand with Semaphore. :)

[dylans]

@ervinb sure, we'd definitely appreciate the help! When I took a brief look at the docs for Semaphore, it wasn't clear where to specify configuration, other than using the Semaphore UI. For example, I see the docs for https://semaphoreci.com/docs/available-environment-variables.html , and I see a few references to a .yml for DB configuration, but can Semaphore read the equivalent of https://github.com/theintern/intern/blob/master/.travis.yml ? Those were my initial questions in the few minutes I spent looking into this to decide to include Semaphore in the list of CI tools to add. I'm sure we'll figure out the answers when we spend some actual time on this, but if you want to accelerate our efforts, we'd appreciate it.

[ervinb]

@dylans Currently, we don't have support for configuration files per se, but the next best thing is to use shell scripts. For example, you'd have a ./scripts/ci.sh file, containing all your settings like dependency installation, language settings, etc. and you can initiate that script in your build steps.

I'd love to help you guys out! Let me know if there's anything else I can do for you.