Upgrading GitLab from 6.7.4 (2f5b6e1) to 7.11

I bit of fun with this particular install (which is has come to be an expectation in regards to installing or updating GitLab:

1. We found out that the update removed the ability to change the target merge branch, once a merge request is created. More: https://github.com/gitlabhq/gitlabhq/issues/7105 
2. Towards the end of the install, the instructions actually disappeared and I could only find the 7.12 instructions. https://gitlab.com/gitlab-org/gitlab-ce/blob/master/doc/update/6.x-or-7.x-to-7.12.md (https://gitlab.com/gitlab-org/gitlab-ce/blob/master/doc/update/6.x-or-7.x-to-7.11.md)
3. In step 3, (sudo -u git -H git checkout 7-12-stable),we had to stash in order to checkout: https://gitlab.com/gitlab-org/gitlab-ce/issues/220
4. There was an error in step 4,(sudo apt-get install nodejs), which I barely noticed, and I had to install nodejs a little differently on debian: https://github.com/joyent/node/wiki/Installing-Node.js-via-package-manager
5.  I accidently followed mysql instructions in step 5, (sudo -u git -H bundle install --without development test postgres --deployment),  and immediately realized it, then ran the postgres instructions. "Gems in the groups development, test, postgres and aws were not installed." Unfortunately, it saved the --without setting and excluded postgresql as well. That led to another error later on in the install. You can fix this by deleting the bundle I believe. http://stackoverflow.com/questions/17871229/rails-application-doesnt-recognize-postgres-gem http://stackoverflow.com/questions/4118055/rails-bundler-doesnt-install-gems-inside-a-group
6. I got the error: unicorn.pid not writable directory for pid=/home/git/gitlab/tmp/pids/unicorn.pid not writable, but I just needed to chown that as it belonged to root.
7. HTTP Push failed (SSH Push was fine), due to having the another ruby version. I changed a symlink to fix it: ln -fs /usr/local/bin/ruby /usr/bin/ruby https://github.com/gitlabhq/gitlab-shell/issues/223 https://github.com/gitlabhq/gitlab-shell/issues/211