- Fix tox.ini syntax
Modern tox versions require the expected environment variables to be
listed one by one on separate lines in tox.ini
- Add `venv` to list of ignored names for git
This is a common name for a local Python virtual environment. Less
typing than `virtualenv`
- Add `tox` to requirements.txt
Installing `tox` via `pip` has the advantage of including it in the
virtual environment, thus avoiding trouble on operating systems shipping
by default with python3.6 or older. It's also nice that `pip install -r
requirements.txt` is now sufficient to set up the testing environment,
after initializing the virtual environment with a moder-enough python
version.
Signed-off-by: Moritz Röhrich <moritz.rohrich@suse.com>
