Gbd-mapping

- Fix requirements.txt (add the click version)

- Add coverage_gap of lack_of_breastfeeding_promotion exposure
- Add coverage_gap of lack_of_lipid_lowering_therapy exposure

- Remove none from causes
- Change risks to risk_factors
- Make coverage_gap available

- Use __about__ in docs
- Split gbd_access into a separate package
- Removing lingering paths
- Fix GbdRecord.to_dict
- Update auxiliary data calls
- Add measles

- Fix deployment issues

- Initial release