- break python-invocations, invoke cycle on tests

- update to 2.1.1:
* The `importlib` upgrade in 2.1 had a corner case
bug (regarding ``from . import `` functionality
within package-like task trees which in turn exposed a
false-pass in our test suite. Both have now been fixed.

- Update to 2.1.0:
- [Bug] #910: Add more rigor around subprocess/runner shutdown
to avoid spurious exceptions & also fix downstream issues in
libraries like Fabric. Reported by Orlando Rodríguez.
- [Bug] #934: The importlib upgrade in 2.1 had a corner case
bug (regarding from . import functionality within
package-like task trees) which in turn exposed a false-pass
in our test suite. Both have now been fixed. Thanks to Greg
Meyer and Robert J. Berger for the bug reports.
- [Bug] #910: Add more rigor around subprocess/runner shutdown
to avoid spurious exceptions & also fix downstream issues in
libraries like Fabric. Reported by Orlando Rodríguez.
- [Support] #901: (via #903) Tweak test suite setup methods to
be named setup_method so pytest stops whining about it. Patch
via Jesse P. Johnson.
- [Bug] #376: Resolve equality comparison bug for
non-collections. Patch via Jesse P. Johnson
- [Support] #901: (via #903) Tweak test suite setup methods to
be named setup_method so pytest stops whining about it. Patch
via Jesse P. Johnson.
- [Support] #906: Implement type hints and type checking
tests with mypy to reduce errors and impove code