Merge pull request #7 from Shinpeim/releng

Releng

Bump version to 0.3.1

Merge branch 'feature/exclusive_polisy_fit_to_rack_session'

Version bump to 0.2.2

Merge branch 'feature/ensure_loaded_when_commit'

Version bump to 0.2.0

Merge branch 'feature/release_0.1.0'

Fix typo