Eliminate N+1 queries in Epics API
This is a follow-up to optimizations in the Todos API: https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/25711.
By preloading the required associations and reusing the
issuable_metadata
keyword from the Todos optimization, we can
eliminate N+1 queries in both the Epics and Todos API.
Edited by Stan Hu