Move continuous integration pipeline to a public provider

[Arithmomaniac]

@kCura is doing a great job setting up CI (see #48), but in the long-term, we should use a hosted or shared service where all project collaborators can view, modify, or kick off jobs, such as AppVeyor.

[mrobustelli]

100% accurate. Relativity is working on a framework (some examples) around how development partners can to this sort of thing. I hope to apply it to Gravity and collaborators will be able to use.

[ppande1020]

Appeveyor would be awesome but we wanted to get developers to be able to run CI easily without being too dependent on a CI tool first and then move towards a shared service.

[Arithmomaniac]

Understood; just wanted to make sure it was on the roadmap.