Fix terminal colors not displaying properly on Windows

[GhostofGoes]

Currently, text colors do not render if using bandit in a Windows terminal interface (both PowerShell and CMD).

Example:

This PR resolves that issue by patching stdout using colorama when running on Windows. Colorama will intercept any ANSI escape codes and convert them to the proper Windows console API calls to change text color (as far as I understand it at least, I'm not a colorama developer).

Example with the fix applied:

Caveats: this adds a dependency on colorama for Windows. It is a very common dependency for Windows Python programs with a CLI interface, is actively maintained, and is licensed under BSD-3.

[ericwb]

Ideally we'd have a CI env running on Windows to test for any breakage there. But Travis-CI for Windows is beta at best.

I applied these changes and tested on Windows 2012 Server command prompt and see the colors now.

[GhostofGoes]

Might want to look into Appveyor, it's like TravisCI but for Windows specifically. And like Travis, it's free for open-source.