Yoga2 dev server breaks when working with git, or saving files too quickly.

[henrysipp]

Describe the bug
When checking out a new branch or pulling changes in Git, Yoga2's develop server tries to reload on itself too quickly, attempting to start a new dev server before the old one has finished shutting down. It throws an "Address already in use" error and dies.

To Reproduce
Steps to reproduce the behavior:

1. Start yoga 2 dev server
2. Check out multiple changed files from git (Or save a file repeatedly, very quickly)
3. Dev server will break after trying to reload too quickly

Expected behavior
Dev server does not die

Versions (please complete the following information):

• OS: macOS Mojave
• Yoga 0.0.20