flake8 fixup

brian_dashboard_manager/config.py

brian_dashboard_manager/grafana/dashboard.py

brian_dashboard_manager/grafana/datasource.py

brian_dashboard_manager/grafana/organization.py

brian_dashboard_manager/grafana/provision.py

brian_dashboard_manager/grafana/utils/request.py

test/conftest.py

test/test_grafana_dashboard.py

test/test_grafana_datasource.py

test/test_grafana_request.py

test/test_update.py