Maintenance updates
- Updates demo codes to import objects from datetime and pandas for pysat 3.0.0 compatibility
- Fixed a bug where test routines used float where numpy 1.18 expects an int
- Import objects from datetime and pandas for pysat 3.0.0 compatibility
- Use conda to manage Travis CI
- Rename default branch as
main
- Update to pysat documentation standards
- Add flake8 testing for code