refactoring: mock whole Emissary class for test_calling_tracker_when_status_query_indicates_started_informs_user(), too
refactoring: mock whole Emissary class for test_calling_tracker_when_status_query_indicates_started_informs_user(), too

geometalab/drf-utm-zone-info,geometalab/osmaxx-frontend,geometalab/osmaxx-frontend,geometalab/osmaxx,geometalab/drf-utm-zone-info,geometalab/osmaxx-frontend,geometalab/osmaxx,geometalab/osmaxx-frontend,geometalab/osmaxx,geometalab/osmaxx