Adding rake to Gemfile. Fixes #48

Created by: paularmstrong

From issue comments...

I had to add rake@0.9.2.2 to the Gemfile because I wanted to run gitlab via an upstart script on Ubuntu, which looks something like...

exec sudo -u www-data sh -c "bundle exec rails s -e production -d >> /var/log/gitlab/gitlab.log 2>&1"

When running bundle/rails from this command, it's unable to find the correct rake dependency and rails will never start.