Johnnydep

What's Changed
* use custom exception type `JohnnyError` when we're raising errors directly (this allows user to `except` the error specifically)
* add graphviz DOT output format

**Full Changelog**: https://github.com/wimglenn/johnnydep/compare/v1.16...v1.17

What's Changed
* make it work with circular dep trees. closes 98. closes 23. by wimglenn in https://github.com/wimglenn/johnnydep/pull/99


**Full Changelog**: https://github.com/wimglenn/johnnydep/compare/v1.15...v1.16

- Allows passing `argv` and `stdout` (i.e. where to print) arguments into `cli.main` explicitly.

- Allow specifying extras after a .whl filename. Fix thanks to Erotemic (89)

* support using local directory as index url (e.g. `-i file:///tmp/wheelhouse/simple`)

- Avoid `UserWarning: Setuptools is replacing distutils.` on Python 3.10+