Support React 17

[loan-laux]

I'm updating segmented-control to React 17 and would need Formsy to support it as well.

There must be a lot of community members who are starting to need React 17 support for their own projects too.

I tried to work on it but quickly got stopped in my tracks because airbnb-prop-types still requires React 16, although that's about to change soon thanks to this PR.

Just filing this issue to:

1. Track progress of React 17 support on airbnb-prop-types
2. For anyone else to work on React 17 support themselves if I don't have time to do it

[rkuykendall]

Cool. I checked airbnb-prop-types in our yarn.lock, and it's from enzyme-adapter-react-16, which is just for testing. So are you sure that formsy production ISN'T React 17 compatible?

If anything, we'd need to wait for the new enzyme-adapter-react-17 which you can follow here: enzymejs/enzyme#2429

[felixmosh]

I'm using React 17 with the latest formsy-react it works fine for 2 month, the only thing that is popped up is the peerDependency warning

[loan-laux]

Indeed. I can confirm that it works well. Sorry about the confusion here, I was initially confused by this peer dependency warning. Looking forward to your PR being merged @felixmosh. Can you add Fixes #583 so that it automatically closes this issue?

[felixmosh]

Published in v2.2.2