Update ruby to latest version.

Change gollum repo to use https:// instead of git://

Attribution as mentioned in https://news.ycombinator.com/item?id=5423635

A lot of people might have firewalls blocking the git:// protocol. Using https:// makes this easier and matches the other git repositories in the Gemfile.

Fix style of network graph.

It is easy to see which branch is merged.

refs #3258

Display commit message on network graph.

Fix column heading order in group admin view

Fix bug with downgrade permissions on first project assigment to team

Fix user path in markdown