Setup vagrant development environment

This commit fixes the issues in the cookbook that prevented it from being used with vagrant and chef-solo. It updates the version of git that is installed as there was a bug with the previous version of git that prevented cloning repositories as another user in the git resource. It also adds the gem_binary path to ensure that all of the gitlab gem dependencies are installed in the correct ruby. It also adds postgresql::server and mysql::server recipes in so that a database server is installed for gitlab to use. It adds service resource blocks for both gitlab and nginx so that both services can be notified to restart after template files are rendered. And finally it updates the chefspec to handle node attributes for the postgresql and mysql server recipes.