New API for deploy key: add/enable a deploy key to a project
Created by: drakeguan
Summary: A new API for deploy key to add or enable an existing deploy key to a project.
In Gitlab API, I spot a way to add a new deploy key to a project, but I can't add an existing one. I have tried to dig the code in lib/api/deploy_keys.rb but it's still hard for me to figure out the way to do that.