Upgrade Babel to 7.0.0 🎉

[Titozzz]

Summary

Thanks to babel team incredible work, they released babel 7 🎉 , here's an update to make sure we are not anymore on a beta version. This will enforce compatibily once every other package updates to babel 7

Test plan

yarn test is OK.

[facebook-github-bot]

Thank you for your pull request and welcome to our community. We require contributors to sign our Contributor License Agreement, and we don't seem to have you on file. In order for us to review and merge your code, please sign up at https://code.facebook.com/cla. If you are contributing on behalf of someone else (eg your employer), the individual CLA may not be sufficient and your employer may need the corporate CLA signed.

If you have received this in error or have any questions, please contact us at [email protected]. Thanks!

[codecov-io]

Codecov Report

❗ No coverage uploaded for pull request base (master@2077b63). Click here to learn what that means.
The diff coverage is n/a.

@@            Coverage Diff            @@
##             master     #233   +/-   ##
=========================================
  Coverage          ?   85.56%           
=========================================
  Files             ?      139           
  Lines             ?     4538           
  Branches          ?      700           
=========================================
  Hits              ?     3883           
  Misses            ?      585           
  Partials          ?       70

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 2077b63...4ee3115. Read the comment docs.

[facebook-github-bot]

Thank you for signing our Contributor License Agreement. We can now accept your code for this (and any) Facebook open source project. Thanks!

[nicolo-ribaudo]

Since Babel 7 releases won't contain breaking change, you can/should use ^7.0.0 everywhere.

[Titozzz]

Oh yeah, sure, silly me 😣

[rafeca]

Yay!! 🎉 I'm also working on an internal commit to upgrade to [email protected].

Since at Facebook we use the master version of Metro we need to do some small tweaks to our internal babel plugins before merging this (there have been some breaking changes between beta.56 and 7.0.0), but this should be ready tomorrow 😊

[Titozzz]

Good to hear @rafeca ! Keep up the excellent work 😀

[Titozzz]

Hey @rafeca , I saw you merged Babel 7 into master, so I guess we can close this pull request ! Would it be possible to bump metro to a new version so that we can create a new RC for react native 0.57 ?

Thanks 🎉