Remove test that causes errors in test shutdown

- using fs_module can cause such errors with some
  combinations of tests
- should fix #687

pyfakefs/pytest_tests/pytest_plugin_test.py

@@ -2,8 +2,6 @@
 import os
 import tempfile
 
-import pytest
-
 from pyfakefs.fake_filesystem_unittest import Pause
 
 
@@ -52,13 +50,3 @@ def test_pause_resume_contextmanager(fs):
         assert os.path.exists(real_temp_file.name)
     assert not os.path.exists(real_temp_file.name)
     assert os.path.exists(fake_temp_file.name)
-
-
-class TestModuleScopedFsWithTmpdir:
-    @pytest.fixture(autouse=True)
-    def test_internal(self, tmpdir):
-        yield
-
-    def test_fail(self, fs_module):
-        # Regression test for #684
-        assert True