Summary:
## The dependency [metro](https://github.com/facebook/metro) was updated from `0.56.3` to `0.57.0`.
This version is **not covered** by your **current version range**.
If you don’t accept this pull request, your project will work just like it did before. However, you might be missing out on a bunch of new features, fixes and/or performance improvements from the dependency update.
---
**Publisher:** [metro-bot](https://www.npmjs.com/~metro-bot)
**License:** MIT
[Find out more about this release](https://github.com/facebook/metro).
---
<details>
<summary>FAQ and help</summary>
There is a collection of [frequently asked questions](https://greenkeeper.io/faq.html). If those don’t help, you can always [ask the humans behind Greenkeeper](https://github.com/greenkeeperio/greenkeeper/issues/new).
</details>
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Your [Greenkeeper](https://greenkeeper.io) bot 🌴
Pull Request resolved: https://github.com/facebook/flipper/pull/622
Reviewed By: jknoxville
Differential Revision: D18268960
Pulled By: passy
fbshipit-source-id: 7dc99729f72978786f301c57b6b0f7d93b49674f
691a4ee135
