Colorama is not being installed in Windows even though it is required

[niander]

Since version 0.8.3 (which has been removed from public feeds) colorama is only added to the list of requirements if the setup.py is executed in a Windows machine. However, knack is being distributed as a wheel package and setup.py is not executed when installing a wheel package. Therefore, knack is broken when executed from a terminal.

conditional dependency needs to follow PEP 508.