Issue #599: test_6 doesn't test anything.

Removed as it was crashing on Windows, achieving nothing on Linux.

tests/test_tools.py

@@ -69,17 +69,5 @@ def test_5():
     file = sys.stdout.read()
     assert file == b""
 
-def test_6():
-    """Test subprocess_call for operation.
-
-    The process sleep should run for a given time in seconds.
-    This checks that the process has deallocated from the stack on
-        completion of the called process.
-
-    """
-    process = tools.subprocess_call(["sleep" , '1'])
-    time.sleep(1)
-    assert process is None
-
 if __name__ == '__main__':
    pytest.main()