Get tests passing locally

When we cloned the repository and started making modifications, we
didn't initially keep tests in step. This commit tries to get us to a
clean test run by skipping tests that are failing and removing some
that we no longer expect to use (MMG, Firetext), with the intention that
we will come back in future and update or remove them as appropriate.

To find all tests skipped, search for `@pytest.mark.skip(reason="Needs
updating for TTS:`. There will be a brief description of the work that
needs to be done to get them passing, if known. Delete that line to make
them run in a standard test run (`make test`).

tests/app/celery/test_tasks.py

@@ -1246,6 +1246,7 @@ def test_save_sms_uses_non_default_sms_sender_reply_to_text_if_provided(mocker,
     assert persisted_notification.reply_to_text == 'new-sender'
 
 
+@pytest.mark.skip(reason="Needs updating for TTS: Remove mail")
 @pytest.mark.parametrize('env', ['staging', 'live'])
 def test_save_letter_sets_delivered_letters_as_pdf_permission_in_research_mode_in_staging_live(
         notify_api, mocker, notify_db_session, sample_letter_job, env):
@@ -1283,6 +1284,7 @@ def test_save_letter_sets_delivered_letters_as_pdf_permission_in_research_mode_i
     assert not mock_create_fake_letter_response_file.called
 
 
+@pytest.mark.skip(reason="Needs updating for TTS: Remove mail")
 @pytest.mark.parametrize('env', ['development', 'preview'])
 def test_save_letter_calls_create_fake_response_for_letters_in_research_mode_on_development_preview(
         notify_api, mocker, notify_db_session, sample_letter_job, env):
@@ -1321,6 +1323,7 @@ def test_save_letter_calls_create_fake_response_for_letters_in_research_mode_on_
     )
 
 
+@pytest.mark.skip(reason="Needs updating for TTS: Remove mail")
 def test_save_letter_calls_get_pdf_for_templated_letter_task_not_in_research(
         mocker, notify_db_session, sample_letter_job):
     mock_create_letters_pdf = mocker.patch('app.celery.letters_pdf_tasks.get_pdf_for_templated_letter.apply_async')
@@ -1404,6 +1407,7 @@ def test_get_sms_template_instance(mocker, sample_template, sample_job):
     ]
 
 
+@pytest.mark.skip(reason="Needs updating for TTS: Remove mail")
 def test_get_letter_template_instance(mocker, sample_job):
     mocker.patch(
         'app.celery.tasks.s3.get_job_and_metadata_from_s3',
@@ -1720,6 +1724,7 @@ def test_process_incomplete_job_email(mocker, sample_email_template):
     assert mock_email_saver.call_count == 8  # There are 10 in the file and we've added two already
 
 
+@pytest.mark.skip(reason="Needs updating for TTS: Remove mail")
 def test_process_incomplete_job_letter(mocker, sample_letter_template):
     mocker.patch('app.celery.tasks.s3.get_job_and_metadata_from_s3',
                  return_value=(load_example_csv('multiple_letter'), {'sender_id': None}))
@@ -1767,6 +1772,7 @@ def test_process_incomplete_jobs_sets_status_to_in_progress_and_resets_processin
     assert mock_process_incomplete_job.mock_calls == [call(str(job1.id)), call(str(job2.id))]
 
 
+@pytest.mark.skip(reason="Needs updating for TTS: Remove mail")
 def test_process_returned_letters_list(sample_letter_template):
     create_notification(sample_letter_template, reference='ref1')
     create_notification(sample_letter_template, reference='ref2')
@@ -1779,6 +1785,7 @@ def test_process_returned_letters_list(sample_letter_template):
     assert all(n.updated_at for n in notifications)
 
 
+@pytest.mark.skip(reason="Needs updating for TTS: Remove mail")
 def test_process_returned_letters_list_updates_history_if_notification_is_already_purged(
         sample_letter_template
 ):
@@ -1793,6 +1800,7 @@ def test_process_returned_letters_list_updates_history_if_notification_is_alread
     assert all(n.updated_at for n in notifications)
 
 
+@pytest.mark.skip(reason="Needs updating for TTS: Remove mail")
 def test_process_returned_letters_populates_returned_letters_table(
         sample_letter_template
 ):
@@ -1917,11 +1925,6 @@ def test_save_api_email_dont_retry_if_notification_already_exists(sample_service
         'app.celery.provider_tasks.deliver_sms.apply_async',
         '07700 900890',
         {'template_type': 'sms'}
-    ), (
-        save_letter,
-        'app.celery.letters_pdf_tasks.get_pdf_for_templated_letter.apply_async',
-        '123 Example Street\nCity of Town\nXM4 5HQ',
-        {'template_type': 'letter', 'subject': 'Hello'}
     ),
 ))
 def test_save_tasks_use_cached_service_and_template(
@@ -1946,7 +1949,7 @@ def test_save_tasks_use_cached_service_and_template(
         wraps=SerialisedTemplate.get_dict,
     )
 
-    for _ in range(3):
+    for _ in range(2):
         task_function(
             service.id,
             uuid.uuid4(),
@@ -1962,9 +1965,9 @@ def test_save_tasks_use_cached_service_and_template(
         call(str(template.id), str(service.id), 1),
     ]
 
-    # But we save 3 notifications and enqueue 3 tasks
-    assert len(Notification.query.all()) == 3
-    assert len(delivery_mock.call_args_list) == 3
+    # But we save 2 notifications and enqueue 2 tasks
+    assert len(Notification.query.all()) == 2
+    assert len(delivery_mock.call_args_list) == 2
 
 
 @freeze_time('2020-03-25 14:30')