Sometimes py.test leave some packages around in tests/config/deps.
Make sure these do not accidentally get pulled into a commit or
cause a local tox run to fail.
This converts the testing infrastructure to tox for both locally
testing and travis. This is nearly equivalent to the previous testing
with the only exception that linting fails with the first tool to fail
and won't process all of them.
Slightly tricky thing is that tox resets *all* of the environment for
it's subprocess runs by default. A couple of the dependencies we have
will not install in non UTF8 locales: temper-python & XBee.
Jan Harkes
Paulus Schoutsen
Dan Smith
Sean Dague