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

========

https://hg.mozilla.org/integration/gaia-central/rev/3eefee4560de
Author: Gareth Aye <gaye@mozilla.com>
Desc: Merge pull request #14994 from gaye/disable-calendar-today

Bug 956064 - Calendar today item marionette orange

========

https://hg.mozilla.org/integration/gaia-central/rev/c1dede75338b
Author: Gareth Aye <gaye@mozilla.com>
Desc: Bug 956064 - Calendar today item marionette orange