Enable lint, flake8 and unit tests

Enable lint, flake8 and unit tests

Cleans up non pep compliant code.
Adds a simple unit test.
Formats according to black.

Tox automatically runs lint, flake8 and unit test suite
with coverage.  To run each individually, execute:

tox -e pylint
tox -e black
tox -e flake8
tox -e cover

Note that these are all run for each patch via Jenkins.  The full
tox suite should be run locally before any commit to ensure it
will not fail in Jenkins.

Change-Id: I2f87abe3d5086d6d65ac33a27780c498fc7b1cd3
Signed-off-by: beierlm <mark.beierl@canonical.com>