R1:a91771801dc7

Remove ReleephBranchBoxView

Summary: Ref T3092. This was obsoleted recently and has no more call/use sites.

Test Plan: `grep`

Reviewers: btrahan

Reviewed By: btrahan

CC: aran

Maniphest Tasks: T3092

Differential Revision: https://secure.phabricator.com/D6779