Introduce better grafana mocking for testing

brian_dashboard_manager/app.py

brian_dashboard_manager/config.py

brian_dashboard_manager/grafana/dashboard.py

brian_dashboard_manager/grafana/organization.py

brian_dashboard_manager/grafana/provision.py

brian_dashboard_manager/inventory_provider/interfaces.py

brian_dashboard_manager/routes/update.py

test/conftest.py

test/test_grafana_dashboard.py

test/test_grafana_datasource.py

test/test_grafana_folder.py

test/test_grafana_organization.py

test/test_update.py

tox.ini