Conlfunece: Subtree method

Polish and cleanup (atlassian-api#377)

* A new Tempo method

* Tempo: add team member

* Bugfix

* Set workload method

* Bump version

* Organize the imports

* Polish

Update rest_client.py

Bump version

Update VERSION

Fix issue with requiremetns.txt on installing pip package

Remove mutable dict as header default value

PYAPI-42 Jira: Add statuses, issues, projects, transitions