Bug 939021 - Follow up to fix build tests. r=me
Bug 946812 - Disable test_camera_flash_modes.py (no flash)
Revert "Bug 946812 - Disable test_camera_flash_modes.py (no flash)"

This reverts commit a7437d8dbef18a955054b20a36b8a69beddee1b9.
Bug 946812 - Disable test_camera_flash_modes.py (no flash)
Merge pull request #15771 from ferjm/travishotfix

Bug 939021 - Follow up to fix build tests. r=me