This commit changes the name of the directory where the python test
code lives so that it is a legal python identifier (no dashes) and
propagates the name change out to all appropriate files.
Additionally, the 'pypy' environment is removed from the default
environments in tox.ini and the 'docs' environment is added as a
default (since creating the user story docs is the whole point of
this repo).
The single test that's there still doesn't do anything, but at least
the framework is correct for when tests are added.
Change-Id: Iacf17ac58e62b67be633c77ea95f6a82d25e7d5a