* Move files for better setup.py packaging
* Update setup.py and configs for src layout
* Run tests on setup.py build
In effect, this tests that the setup.py configuration is correct.
coverage combine and coverage:paths are added to keep the displayed
coverage paths as src/ssh_audit/*.py instead of
.tox/$envname/**/site-packages/ssh_audit/*.py
* Remove unnecessary encoding declarations
Python 3 defaults to UTF-8 encoding.
https://docs.python.org/3/reference/lexical_analysis.html#encoding-declarations
* Remove shebang from colorama type stubs
Shouldn't need to be an executable.
Related: git has this file tracked as chmod -x.
