Metadata update and cleanup

* Updated tox and travis configuration
* Formatting fixes to the README
* Moved licence to README
* Use setuptools
* Add pep8 and pyflakes to tox
Cleaned up codebase, replaced tabs with spaces
2.0.0 stable release

Python-colorlog is no longer marked as 'beta' software. I have no
plans to add new features for now, but will continue to maintain it
if/when bugs or problems are discovered.