Add React 18 support

[gaearon]

Basic support to get people unblocked.

Closes #110.
Closes #109.

[ljharb]

Changes look good, but unfortunately CI isn't testing on multiple react versions.

[gaearon]

I've verified all tests pass with 16 except the ones with new APIs.

[gaearon]

I'm not sure what's up with the CI not running. I also don't have merge rights in this repo. Can I have them pls?

[ljharb]

You do already, but the branch protections aren't running, it seems. @NMinhNguyen?

[NMinhNguyen]

Not sure why CI isn't wired up, but I can see this build failed https://app.circleci.com/pipelines/github/enzymejs/react-shallow-renderer/143/workflows/a58d521f-9141-41af-b11a-282cbf426bab/jobs/140

[NMinhNguyen]

@ljharb are you able to follow https://circleci.com/docs/2.0/enable-checks/ to enable GitHub Checks? I don't think I'm an admin, so I can't enable it.

[gaearon]

I don't have permissions to Organization Settings so I can't follow that guide.

[gaearon]

The last build passed. I don't think I can fix CI without more permissions but let's get this released as a minor?

[gaearon]

In the interests of getting this out, I plan to publish from my branch locally. Then when CI is fixed, I'll push a version bump to main.

[NMinhNguyen]

I propose temporarily disabling status checks if the CircleCI integration isn't fixed in the next, say, 10 minutes. Then we can merge this PR, bump the version on main and npm publish.

[gaearon]

Published as [email protected]. The change is pretty simple and I'm happy to monitor and fast-follow in case there are any problems.

[ljharb]

I'll take a look at circle right now; @NMinhNguyen, you are a repo admin, but it might take org ownership.

[ljharb]

https://app.circleci.com/projects/project-dashboard/github/enzymejs/ should now be set up; let me know if there's something more i need to do.

[NMinhNguyen]

@ljharb thanks. I've raised #116 to check whether CI works