Remove unused Ruby implementation for CommitStats
Commit stats are new served by Go, and the implementation can be removed from the Ruby sidecar.
MR of the Go port: !1048 (merged) Closes #1471 (closed)
Commit stats are new served by Go, and the implementation can be removed from the Ruby sidecar.
MR of the Go port: !1048 (merged) Closes #1471 (closed)