- Removed unneeded vagrant-rsync-gatling settings.
- Enabled rsync-auto by default (even if not using gatling).
- Exclude *.pyc and __pacache__ from rsync.

- Imporoved docmentation for development.

- Renamed test file and function because otherwise test detection fails.
- Set py.test to verbose.
- Moved flake8 settings from tox.ini to setup.cfg (in case of moving away from
  tox).

- Didn't specify minor Python versions (just 2 and 3).
- Removed test make target, instead use tox.
- The make clean target removes just unshare/constants.py now.
- Removed testing packages from dev dependencies and the test dependency list,
  dev depends just on tox (the other packages are install in the virtualenv).
- Cleaned tox.ini a bit.

- Renamed test file for py.test.

- Added .cache to gitignore.
- Corrected some flake8 whitespace errors.
- Disabled 'from unshare import *' flake8 error.