Bumping gaia.json for 2 gaia revision(s) a=gaia-bump

========

https://hg.mozilla.org/integration/gaia-2_0/rev/d84f144b5998
Author: Zac <zcampbell@mozilla.com>
Desc: Bug 1022132 - Disable test_a11y_unlock_to_homescreen.py

========

https://hg.mozilla.org/integration/gaia-2_0/rev/59cd5f071bf8
Author: Zac <zcampbell@mozilla.com>
Desc: Bug 1027708 - test_homescreen_edit_mode.py intermittent due to unknown MacOS bug a=testonly r=me
Bumping manifests a=b2g-bump