Tox to test across Python versions

Tox as 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.

Install multiple Python versions locally

https://github.com/utahta/pythonbrew - Pythonbrew is a program to automate the building and installation of Python in the users $HOME.
https://github.com/akheron/multipy - Install multiple Python versions locally