Version bump: 0.3.0

- Developer docs, release process (fixes #14)
- Broke tests into their own path, split them out by module
- Using semantic_version instead of verlib
- Linted the crap out of stuff
  - No more sphinx warnings!
  - Normalized quotes: Single quote for strings, double quotes for docstrings
  - Lint expectations outlined in dev docs
- unittest2 is now in tests_require where it belongs (fixes #16)
- Brought in the Mapping tyoe from PR #15 (fixes #17)
  - Thanks, @aquamatt!