Update installation.md
Update installation.md: Correct Postgresql username and move user creation above database prep.
Merge branch 'fixes_in_install_guide' of /home/git/repositories/gitlab/gitlab-ci into 3-1-stable
Checkout the right branch in installation docs
Merge branch 'checkout_3_1' of /home/git/repositories/gitlab/gitlab-ci into 3-1-stable
adding minitest to Gemfile
rewriting ansi2html

adds support for
- background color (16 and 256 color tables)
- normal and bright color (16 color table)
- bold text
- italic text
- underlined text
- crossed-out text
- concealed text