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

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https://hg.mozilla.org/integration/gaia-central/rev/5b9c6ec87161
Author: Zac <zcampbell@mozilla.com>
Desc: Merge pull request #15386 from zacc/bug_946205

Bug 946205 - Re-enable Travis tests after 891882 merged

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https://hg.mozilla.org/integration/gaia-central/rev/b3ab46a372eb
Author: Zac Campbell <zcampbell@mozilla.com>
Desc: Bug 946205 - Re-enable Travis tests after 891882 merged
Bumping manifests a=b2g-bump