Pysatmissions

* Use conda to manage Travis CI environment
* Updated style to be compliant with pandas 2.0 and pysat 3.0
* Import datetime from datetime
* import DataFrame and Series from pandas rather than pysat
* Rename default branch as `main`

* Renamed as pysatMissions
* Added method files to access aacgmv2, apexpy, pyglow for any pysat instrument
* Added method for spacecraft to handle attitude and coordinates
* Added method for plotting simulated data
* Added support for readthedocs
* Updates to testing environment
* Split pysat_sgp4 into pysat_sgp4 and pysat_ephem to allow different propagators
* Removed basemap
* Added numeric strings as options for sat_id
* Added `_get_times` to streamline time steps for simulated instruments
* Bugs
* Fixed wrong metadata name for mlt in apexpy

* pypi compatibility
* Add DOI badge

* Initial release