Sedas-pyapi

This release contains changes for which you will need to update your code.

* Make the login step optional making it easier to access the test environment. Note: you will now need to manually call
sedas.login()

* Add useragent header to stop the SeDAS firewall getting cross

* Fix bulk download threads stopping on errors

This release contains potentially backwards incompatible changes.

* Add source group lookup
* Add satellite lookup
* Make source group and satellite name optional on type specific searches
* Remove underscores from parameter names on all SeDASAPI functions (this may break existing code with named parameters)

* Add Source Group search parameter
* Add Satellite Name search parameter

* Documentation updates
* Download done queue added to bulk downloader