Add rake task 'gitlab:update_commit_count'
Starting with migration 20150717130904
commit count is stored in the
database. For existing projects it defaults to 0
and is updated to the
correct value when commits are pushed.
The newly introduced rake task updates the commit count for all projects which have not been updated yet.
Refs !986 (merged), !989 (merged), #2040 (closed), #2089 (closed).