Bumping gaia.json for 1 gaia revision(s) a=gaia-bump

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https://hg.mozilla.org/integration/gaia-2_0/rev/606f5138c56f
Author: Dave Hunt <dave.hunt@gmail.com>
Desc: Bug 1028254 - Bump marionette client dependency to 0.7.10. r=ahalberstadt
Bumping manifests a=b2g-bump