Some tests have no expected fixture

The following test cases aren't actually being run due to "expected" fixtures not existing for them. I'm not sure how this impacts our test coverage, but I wanted to call it out so if someone else runs into this they know what's up. I feel like we talked about this a while ago @ziafazal , but I don't remember what the deal was.

• TestCaliperTransformers::test_event_transformer_05_edx_course_enrollment_mode_changed_json

• TestCaliperTransformers::test_event_transformer_09_problem_check_server__no_response_type_json

• TestCaliperTransformers::test_event_transformer_12_edx_forum_thread_created_json

• TestCaliperTransformers::test_event_transformer_13_problem_check_server_unsupported_responsetype__json

• TestCaliperTransformers::test_event_transformer_17_edx_course_grade_now_failed_json

• TestCaliperTransformers::test_event_transformer_22_edx_grades_problem_submitted_weighted_possible_0_json

• TestCaliperTransformers::test_event_transformer_24_edx_video_closed_captions_hidden_null_duration_json

• TestCaliperTransformers::test_event_transformer_27_problem_check_server_string_anwers__json

• TestCaliperTransformers::test_event_transformer_34_load_video_required_only_data_json

• TestCaliperTransformers::test_event_transformer_35_edx_forum_thread_deleted_json

• TestCaliperTransformers::test_event_transformer_39_edx_forum_thread_viewed_json

• TestCaliperTransformers::test_event_transformer_40_problem_check_server__max_grade_0_json

• TestCaliperTransformers::test_event_transformer_43_edx_forum_thread_edited_json

• TestCaliperTransformers::test_event_transformer_47_edx_course_grade_now_passed_json

• TestCaliperTransformers::test_event_transformer_49_edx_forum_thread_voted_json

• TestXApiTransformers::test_event_transformer_04_postion_changed_video_json

• TestXApiTransformers::test_event_transformer_24_edx_video_closed_captions_hidden_null_duration_json

• TestXApiTransformers::test_event_transformer_46_play_video_required_only_data_json

Locate the TestCaliperTransformers and TestXApiTransformers cases listed in the issue and inspect how their expected fixtures are discovered. Run the affected tests to confirm which cases are skipped or fail; done means each listed case has an expected fixture and is actually executed successfully.