Remove Koding in GitLab 11
This was discussed in the Summit UGC session "What should we remove from GitLab?". Koding integration is already deprecated and we announced we will remove Koding completely in GitLab 11.0, per https://about.gitlab.com/2017/09/22/gitlab-10-0-released/#koding-integration. I didn't see an existing issue for this so I am creating this one. If this is a duplicate, please link and close this one.