Remove "Reviewed By" Differential field
Summary: Ref T11114. This is replaced by DifferentialReviewedByCommitMessageField.php.
Test Plan:
- Used differential.getcommitmessage to query an accepted revision, saw "Reviewed By".
- Grepped for removed class name.
Reviewers: chad
Reviewed By: chad
Maniphest Tasks: T11114
Differential Revision: https://secure.phabricator.com/D17079