Not necessary for CI testing, as the environment is always completely
recreated. Developers can add '-r' to their command lines to recreate
the environments when needed. The CI testing should catch issues if
something works locally only due to an environment anomaly.
From the project webpage:
"""
Tox is a generic virtualenv management and test command line tool you can use
for:
- checking your package installs correctly with different Python versions and
interpreters
- running your tests in each of the environments, configuring your test tool of
choice
- acting as a frontend to Continuous Integration servers, greatly reducing
boilerplate and merging CI and shell-based testing.
"""
