Tox-poetry-installer

- Add support for Poetry-1.2.x. Contributed by [Justin Wood](https://github.com/Callek)
(73)
- Update Black formatting to stable release version
- Remove support for Python-3.6
- Remove support for Poetry-1.1.x
- Fix installing dependencies multiple times when transient dependencies are duplicated in
the dependency tree

- Fix Poetry version specification supporting the incompatible Poetry-1.2.0 release

- Fix issue where incompatible package versions were selected for installation when
multiple package versions were in the lockfile

- Add PyPI classifier for Python 3.10 compatibility

- Improve debug-level logging for package installation, and time how long installing each
package takes. Contributed by [Rebecca Turner](https://github.com/9999years) (#63).
- Fix crash caused by the package-under-test depending on Poetry's unsafe dependencies
([65](https://github.com/enpaul/tox-poetry-installer/issues/65))

- Fix unintuitive behavior of the `install_project_deps` option by ensuring the specified
value always causes the implied action