Remove fast-forward merge as EES feature after being ported to CE

Open username-removed-892863 requested to merge move-fast-forward-merge-strategy-to-ce into master

Remove fast-forward merge as EES feature after being ported to CE

Was listed under EES here, https://about.gitlab.com/products/

See https://gitlab.com/gitlab-org/gitlab-ce/issues/20076


cc @victorwu Is there protocol for when this should be merged for the 10.1 release?

Edited by username-removed-892863