Project branch naming logic

Added logic for naming git branches when creating/renaming branches.

BUG=chromium:980346
TEST=new and existing unit tests

Change-Id: Ia773c399d8445e63c3fd0ebbae9d3187e3425430
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/infra/go/+/1695711
Reviewed-by: Evan Hernandez <evanhernandez@chromium.org>
Commit-Queue: Jack Neus <jackneus@google.com>
Tested-by: Jack Neus <jackneus@google.com>
8 files changed