Sevenbridges-python

- Bugfixes:
- Fixed logic for oauth authorization

- Bugfixes:
- Don't send default values for task execution settings
- Fixed updating of execution settings during Task save method

- Improvements:
- Upload part_size will use a value returned by server, the provided value will be used as a suggestion that may be accepted by the server
- Improved and added many debug logs
- Bugfixes:
- Fixed issue with using folders as task inputs

- Improvements:
- Added other task query parameters to get_batch_children Task method, including limit and offset (for pagination)

- Improvements:
- Exposed created_on, created_by, modified_on fields on Project entity.

- Improvements:
- Added ABORTING to TaskStatus enum