Improve coreapi importing

[gsvr]

Description

Closes #5918
Import coreapi from rest_framework.compat, not directly.

[DEKHTIARJonathan]

Please release a new version on PyPI as soon as this PR is merged ;)

Thanks for the work

[gsvr]

@carltongibson I hope I opened this PR in the right way, first time contributing 😅
I did two additional things to what you stated in the issue:

1. Added and coreschema is not None, not sure if this was necessary but it looked safer.
2. Changed the import in test_renderers.py - I doubt this is necessary but it's more consistent with other imports in tests.

Please let me know if you want a test for this, it didn't look like something you were testing generally.

[carltongibson]

@gsvr Thanks for this.

@ALL: This will go into a 3.8.2. There are a couple of issues for that, so it'll be first half of next week. If you cannot wait until then you should install directly from GitHub. (Pip has first-class support for this. It's not something to avoid.)

[carltongibson]

Yep. Looks good.

[gsvr]

@carltongibson It's not a problem for me, I just pinned my version to <3.8 for now. Thanks for the quick responses :)

[carltongibson]

v3.8.2 is now available on PyPI. Thanks all.

[xordoquy]

@LuisHCK please, don't use passive aggressive tone.
We - anyone that contributed here - have no part in your code not working as you'd have wished/expected.
You just don't bring anything valuable to the issue here beside negative comments.
Please, be constructive. Write the simplest possible test case where you can show your issue and open a PR so we may look at it.

[rpkilby]

@LuisHCK. These changes are included in the 3.8.2 release (see: here). I would check again what version of DRF is installed. You may also want to recreate your virtual environment.