Vivarium-public-health

- Implement LinearScaleUp component
- Refactor Risk, RiskEffect, and Mortality components for inheritance
- Added pull request template
- Fix bug in excess mortality pipeline name
- Fix bug in risk propensity pipeline

- Update license to BSD 3-clause
- Add .zenodo.json metadata replacing AUTHORS.rst

- implement categorical risk observer
- fix pandas warning in application of risk effect
- fix column name bug
- improve performance of reshaping
- require 2.0.6 and later of risk_distributions

- Fix bugs in DiseaseState
- Improve functionality of ensemble distributions
- Improve CI

- Fix bug in computing ages from an age distribution

- Improve standard DiseaseObserver
- Add 'transition rate' to the RateTransition object
- Add state and transition names to DiseaseModel and RiskAttributableDisease
- Get location from artifact rather than config file
- Fix bug that resulted in non-unique initializations of populations