Upgrade prettier

[kirkstrobeck]

1.3.1 is out. This is still on 1.3.0. Ideally, something like greenkeeper would always fetch the latest on a daily basis, since it’s a core dep.

[kentcdodds]

This package is using "prettier": "^1.3.0", so we shouldn't need to actually update the dependency until prettier v2.0.0 comes out. Just reinstall deps and you should be good.