Investigating GitLab

Thanks! Documentation is one place that needs to be improved (namely the configuration file and, yes, deployment). There are some issues that would probably be nice-to-have for other deployments (like storing check configuration in the repository itself), but they haven't been high priority for us. Once I get these done (maybe I'll find time this weekend for deployment docs at least), I'll report back here.

A quick overview of deployment is that there are 2 binaries, webhook-listen and ghostflow-director. The first is for a never-goes-down webhook listener so that webhooks are always delivered even if the director is restarting or down or whatever. It verifies webhooks and classifies them as well. The second does the actual git manipulations with a local clone of the repository. They're also designed so that there's no (non-configuration) state that isn't stored in the repository or service itself. For the service-side, GitLab just involves making an account and giving it Maintainer permissions on the repositories it will act on. Github involves creating an App and an associated account (for an SSH key). Both services require an SSH key it can use for pushing to the relevant repositories.