Bump version: 2.4.0 → 2.5.0

PEP-396 module version attribute.

Removes the version object in `cheat.version`
Adds a `cheat.__version__` string attribute

Add filters setting

Refactors cheat/utils colorize functions.

CHEATSTYLE can now be an ordered list of style names to try
CHEATFILTERS can now be a mapping of filters to apply, if available

Add pygments style config

Fixes script shebang

Fixes version output from bin/cheat

Versioning using setuptools_scm

v2.1.8

- Added cheatsheets
- Docopt template change

v2.1.27

- cheatsheet additions
- various bug fixes

v2.1.26