Fixed
- Fixed bug with background callback requiring cellery worker or diskcache, due to Dash 2.7.0 upgrade
- Fixed read the docs templates list accordions not displaying
- Changed dockerfile to use non root user; credit [jasonwashburn](https://github.com/jasonwashburn)
- Fixed CI/CD build process to install dashtools tar file; credit [jasonwashburn](https://github.com/jasonwashburn)