- Added `ci/lint.sh`, which uses `flake8` to lint the relevant files
- Made changes to appease the linter.
- Bugfix in `cheat/configuration` (missing dependency)
- Extracted `Colorize` class out of `Util` class. (The latter now only
contains static methods.)
- Renamed methods in `Colorize` class for improved clarity.
- Refactored as necessary to accommodate the changes above.