Release 0.22.1

Minor bug fix release. Changes are:

- Switch to joblib.dump and joblib.load for serialization (should fix #94)
- Switch to using official drmaa-python release now that it's updated on PyPI
- Fix issue where training examples were being loaded for pre-trained models (#95)
- Change to using `entry_points` to generate scripts instead of `scripts` in `setup.py`, and utilities are now in a sub-package.