….x, and Windows development support.

Tested against NiFi-1.28.1 and 2.2.0.
Bumped minimum Python3 version to 3.9 in line with Python retirement dates.
Minor linting fixes.
Corrected version checks for Templates deprecation in NiFi-2.x
Added catcher for attempting to call Template functions against NiFi-2.x throwing new nipyapi.utils.VersionError, updated tests to match.
Library should now throw VersionError for client-server mismatch instead of generic ValueError with a 404 Not Found inherited from Requests.
Resolved fixture issues related to template create/destroy operations during pytest execution.
Switched default Controller Service Type to CSVReader from DistributedMapCacheClientService as it is present in all tested versions.

Updates to supported versions, handing Template deprecation in NiFi-2.x, and Windows development support

* Add support for mTLS.
* Added Python3.10 as it historically had urllib3 changes that caused issues.
* renamed the 'secure' test mode to 'secure-ldap' distinguish it from 'secure-mtls'.
* Added 'secure-mtls' test mode with docker configuration and pytest setup.
* Added including 'reporting tasks' to some controller functions as the management controllers fall into that group and the SSL Context controller required for secure registry falls into that category.
* Changed the default_proxy_user in config.py to user1 instead of localhost to match the certs.
* Added optional 'purpose' overide to security/set_service_ssl_context to handle certificates needing to be either CLIENT or SERVER auth. Should fix issue #370.
* bootstrap_security_policies changed to read system_diagnostics and policies by default. Added mtls handling. Added default registry policy setup for the nifi proxy user.
* Added security.py function to create_ssl_context_controller_service which is required to create the registry client in an mTLS environment.
* Updated utils/set_endpoint to handle correctly setting the SSL Context for mTLS when login is not requested, and not just LDAPS. This allows easy mTLS usage as shown in conftest.
* updated versioning/create_registry_client to accept an SSL Context Service to setup the secure registry connection under mTLS.
* Locked latest for testing to be 1.28.1 for this branch of NiPyAPI as testing against 2.x is not a full test suite.
* pytest now has an additional mode secure_mtls, which clones the secure_ldap setup. You can only use either mtls or ldap concurrently as they share network names in the certificates.
* Added include_reporting_tasks option to get_controller
* adopted recommended SSLContextService type from NiFI docs

Fixedup docs for swagger-codegen-cli to point at version 2.4.41
Fixed linting in primary client

Updated nifi and registry low level clients to v1.28.1

* Update history for release

* Bump version: 0.21.0 → 0.22.0

Add Otto Fowler to list of Contributors, thanks Otto!
Removed Py2 compatibility methods and imports
Removed python header encoding and env statements
Regenerated clients using updated templates

Deprecate Travis CI

Deprecate Python2 support

…ient class. (#387)