------------------------------------------------------------------------------
Added
~~~~~
- Debugging on lines starting with : comments (https://github.com/pybel/pybel/issues/162)
- Added missing relations in pybel constants (https://github.com/pybel/pybel/issues/161)
Changed
~~~~~~~
- Merge definition and graph cache (https://github.com/pybel/pybel/issues/164)
- Warn when not using semantic versioning (https://github.com/pybel/pybel/issues/160)