Include branch field in review request emails

Review Request #10147 — Created Sept. 16, 2018 and submitted — Latest diff uploaded

Information

Review Board
release-3.0.x
f21537d...

Reviewers

With a lot of review request emails, prioritizing review requests emails
becomes uneasy.

Review request e-mails will now contain a branch field.

Tested by manually checking generated review request emails for the
inclusion of the branch field.