Converted src tree to be PEP8 compliant

Included the revelation of an untested codepath in src.util.locations and the
addition of the necessary tests, some "pragma: no cover" for a couple of
corner cases that were originally marked as "no cover" on a single line.
Converted all unit tests to be PEP8 compliant.
Converted E2E tests to PEP8

Completes unit test conversion.
Merge branch 'refactor/pep8-compliance' into dev