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

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https://hg.mozilla.org/integration/gaia-central/rev/8af07726968d
Author: Anthony Ricaud <anthony@ricaud.me>
Desc: Merge pull request #14204 from Rik/change-reporter-944279

Bug 944279 - Use the spec reporter for all mocha suites r=yurenju

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https://hg.mozilla.org/integration/gaia-central/rev/2bb8d22fd0d0
Author: Anthony Ricaud <anthony@ricaud.me>
Desc: Bug 944279 - Use the spec reporter for all mocha suites