Added link to the configuration sample for OmniAuth providers when using Omnibus.
Merge branch 'omniauth-config-sample-link' into 'master'

Add link to OmniAuth config sample for Omnibus

Added a link to the OmniAuth config sample for Omnibus installations.

See merge request !1335
Merge branch 'master' of github.com:gitlabhq/gitlabhq
Merge branch 'master' of github.com:gitlabhq/gitlabhq
Merge branch 'master' of github.com:gitlabhq/gitlabhq