Merge pull request #12386 from cpennington/cale/concurrent-unit-tests

cms/envs/test.py

...on/djangoapps/external_auth/tests/test_openid_provider.py

common/lib/xmodule/xmodule/contentstore/mongo.py

common/lib/xmodule/xmodule/modulestore/__init__.py

common/lib/xmodule/xmodule/modulestore/mixed.py

common/lib/xmodule/xmodule/modulestore/mongo/base.py

...odule/xmodule/modulestore/split_mongo/mongo_connection.py

common/lib/xmodule/xmodule/modulestore/split_mongo/split.py

common/lib/xmodule/xmodule/modulestore/tests/django_utils.py

...odule/xmodule/modulestore/tests/test_split_modulestore.py

...odule/xmodule/modulestore/tests/test_split_w_old_mongo.py

...n/lib/xmodule/xmodule/partitions/tests/test_partitions.py

docs/en_us/internal/testing.rst

lms/djangoapps/ccx/api/v0/tests/test_views.py

...jangoapps/course_wiki/tests/test_comprehensive_theming.py

lms/djangoapps/courseware/tests/test_views.py

lms/djangoapps/dashboard/git_import.py

...ashboard/management/commands/tests/test_git_add_course.py

lms/djangoapps/dashboard/sysadmin.py

lms/djangoapps/dashboard/tests/test_sysadmin.py