Fossology

The `download_report()` function now gets the name of the report generated by the Fossology server from the HTTP response header and returns both the report content, and the report filename. See [documentation]( https://fossology.github.io/fossology-python/report.html) for details.

This is a small but **breaking change** compared with the previous version, Fossology clients source code will need some **minor adaptation** if an upgrade is performed.

Add `wait_time` option to improve configurability depending on the size of the uploaded file.

Honour Retry-After header from GET uploads

* Add switch to support URL upload and document the different upload types: file, VCS and URL.
* Add upload `filesha1`
* Improve compatibility with future API objects by using keyword arguments
* Bug fix: remote use of Walrus operator to ensure compatibility with Python 3.6 and 3.7

* Add upload argument to method `list_jobs()`, closes 21
* Add options to wait for job completion in methods `schedule_jobs` and `detail_job()` as suggested in 20
* Update to REST API version 1.0.13:
* `DELETE /users/{id}`
* `GET /uploads/{id}/licenses`
* Add `ignoreScm` and `groupName` options for `POST /uploads`
* Add `groupName` option for `DELETE /uploads/{id}` and `PATCH /uploads/{id}`
* Breaking change: use Upload object instead of `upload_id` in method `upload_summary`
* Improve exception handling by sending raw server response in case no JSON is returned
* Fix implementation of specific agents handling, extend test
* Fix styling/formatting, shorten list of flake8 ignores
* Add test coverage in actions and export badge on README (using codecov)
* Improve coverage rate to 83%, fix some bugs on the way
* Extend copyright to 2020 on source files

Add possibility to customize scan agents depending on the Fossology instance.