Force Releeph to be installed during unit tests

Summary: Fixes failure in "testApplicationInstalled" if this flag is off (as it is by default).

Test Plan: Ran "testApplicationsInstalled" with this flag off.

Reviewers: garoevans, btrahan

Reviewed By: btrahan

CC: aran

Differential Revision: https://secure.phabricator.com/D5979