------
* Dropped support of Python 2.7, 3.5, 3.6
* Fixed issue with type annotation for `responses.activate` decorator. See 468
* Removed internal `_is_string` and `_ensure_str` functions
* Removed internal `_quote` from `test_responses.py`
* Removed internal `_matches` attribute of `RequestsMock` object.
* Generated decorator wrapper now uses stdlib features instead of strings and exec
* Fix issue when Deprecation Warning was raised with default arguments
in `responses.add_callback` due to `match_querystring`. See 464