Git repositories in rb-gateway can now pull from an upstream remote.

Review Request #9347 — Created Nov. 4, 2017 and updated — Latest diff uploaded

Information

rb-gateway
master
88a011a...

Reviewers

A Pull method was added to repository.go and git_repository.go.
This method is intended to behave like git-pull meaning it starts with
a git-fetch and then a git-merge. Fetching is made rather
straightforward thanks to git2go. However, the merge section of Pull
required a few more steps. First, a merge analysis is performed, then the
merge and lastly a commit is created.

I setup a remote repository on github, cloned it on my machine, pushed
a few changes and pulled those changes into my local copy using only
RB-Gateway's Pull method.