New cis v1.20 (#912)

* Add files via upload

* Add new cis support v1.20!

* Fix issue with 1.1.9 and 1.1.10 tests

Tests in some cases stat empty path which will return error.

* Add tests for kubernetes 1.20 and retire 1.15 tests

kubernetes 1.15 is not supported anymore and we shouldn't keep testing it.

* Kubernetes 1.15 is not supported anymore

* Tests for kubernetes 1.20

* Fix yamllint errors

Removed trailing spaces (trailing-spaces)

* Add tests for v1.20

* Remove extra spaces

* Change cis test functions names