Removed old test runner test cases.

These files were added as part of #12658, which pertained to the old django.test.simple test runner. No tests call them anymore.

tests/runtests.py

@@ -34,7 +34,6 @@ SUBDIRS_TO_SKIP = [
     'test_discovery_sample',
     'test_discovery_sample2',
     'test_runner_deprecation_app',
-    'test_runner_invalid_app',
 ]
 
 ALWAYS_INSTALLED_APPS = [

tests/test_runner/valid_app/__init__.py

@@ -1,3 +0,0 @@
-# Example of app layout to verify that the fix for #12658 doesn't break test
-# discovery when both `models` and `tests` are packages.
-# `test_runner` tests perform test discovery on this app.

tests/test_runner_invalid_app/__init__.py

@@ -1,4 +0,0 @@
-# Example of app layout that causes issue #12658:
-# * Both `models` and `tests` are packages.
-# * The tests raise a ImportError exception.
-# `test_runner` tests performs test discovery on this app.

tests/test_runner_invalid_app/tests/__init__.py

@@ -1,4 +0,0 @@
-# Tests that raise ImportError should not fail silently.
-# This is a support fixture for one test case in test_runner
-
-raise ImportError