Flask-cors

* Include examples to specify that schema and port must be included in … by YPCrumble in https://github.com/corydolphin/flask-cors/pull/294
* two small changes to the documentation, based on issue 290 by bbbart in https://github.com/corydolphin/flask-cors/pull/291
* Fix typo by sunarch in https://github.com/corydolphin/flask-cors/pull/304
* FIX: typo in CSRF by sattamjh in https://github.com/corydolphin/flask-cors/pull/315
* Test against recent Python versions by pylipp in https://github.com/corydolphin/flask-cors/pull/314
* Correct spelling mistakes by EdwardBetts in https://github.com/corydolphin/flask-cors/pull/311
* 'Access-Control-Allow-Private-Network = true' header for http response by chelo-kjml in https://github.com/corydolphin/flask-cors/pull/318
* docs: Fix a few typos by timgates42 in https://github.com/corydolphin/flask-cors/pull/323
* [Docs] Fix typo in configuration documentation by sachit-shroff in https://github.com/corydolphin/flask-cors/pull/316

Adds support for PPC64 and ARM64 builds for distribution. Thanks sreekanth370

Security
- Escape path before evaluating resource rules (thanks to Colby Morgan). Prior to this, flask-cors incorrectly
evaluated CORS resource matching before path expansion. E.g. "/api/../foo.txt" would incorrectly match resources for
"/api/*" whereas the path actually expands simply to "/foo.txt"

Fixes : DeprecationWarning: Using or importing the ABCs from 'collections' in Python 3.7.
Thank you juanmaneo and jdevera for the contribution.

Updated logging.warn to logging.warning (234) Thanks Vaibhav

Manual error in release process. Identical contents at 3.0.5.