try to remove no test ran line

Author: Tieqiong

run_tests.py

@@ -2,5 +2,9 @@
 
 import diffpy.pdfgui.tests
 
-assert diffpy.pdfgui.tests.test().wasSuccessful()
-assert diffpy.pdfgui.tests.testdeps().wasSuccessful()
+def run_tests():
+    assert diffpy.pdfgui.tests.test().wasSuccessful()
+    assert diffpy.pdfgui.tests.testdeps().wasSuccessful()
+
+if __name__ == '__main__':
+    run_tests()