Multiple Git Provider Support

[acrosman]

Currently there is great support for github, but the flows for ci_feature, ci_master, etc assume that's the repository service is use, making them non-functional for companies that use other services like Bitbucket or GitLabs.

It would be great to add support for other services, or at least flows that are service agnostic (rely entirely on the local repository). Without that it appears we need to create our own custom flows to be able to have a single command to create a QA org and run all the automated tests. If that's not correct I would love to be corrected.