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

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https://hg.mozilla.org/integration/gaia-central/rev/36aa3e5d226a
Author: Jonathan Griffin <jgriffin@mozilla.com>
Desc: Merge pull request #12862 from zacc/bug927002

Bug 927002 bump minimum marionette client version to 0.6

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https://hg.mozilla.org/integration/gaia-central/rev/beb30c1d8784
Author: Zac Campbell <zcampbell@mozilla.com>
Desc: Bug 927002 bump minimum marionette client version to 0.6 after breaking changes to marionette client