Update installation.md

Updating docs to reflect current install steps
Update installation.md
Merge pull request #206 from SteveRyherd/master

Updating docs to reflect current install steps.
Fixed installation docs
Fix adding runner to project
Merge branch 'master' of github.com:gitlabhq/gitlab-ci
Fix error message saying deploy key was not added
Show runner at build page. Add db index
Typo fix: name of postgresql database.yml template.
Merge pull request #215 from jperville/patch-2

Typo fix: name of postgresql database.yml template.
Merge branch 'master' into patch-3

Conflicts:
	doc/installation.md