Python 3 script that adds a maintenance window on all services

…indow_all_services.py

end_all_maintenance_windows.py

Python v3/v2 samples are adequately represented by the v3 samples, because the
only difference as yet is print statement syntax (and Python 3's is backwards
compatible), and there's little chance we will run into significant differences
between the Python files to warrant doubling the number of files that will need
to be maintained.

Additionally, this commit fixes some typos (i.e. functions named
`trigger_incident` where `resolve_incident` would be more appropriate).

Escalation policy schema corrected for Service update API

create_maintenance_window_all_services.py

[AE-167] remove team_responder from API_Python_Examples