Small change to regtests.

regtests/regtests.py

 import os
+import sys
 import unittest
 import logging
 import numpy as np
@@ -1358,4 +1359,6 @@ if __name__ == '__main__':
         suites.append(unittest.TestLoader().loadTestsFromTestCase(TestElectronicStructureMethod))
 
         alltests = unittest.TestSuite(suites)
-        unittest.TextTestRunner(verbosity=0).run(alltests)
+        result = unittest.TextTestRunner(verbosity=0).run(alltests)
+
+        sys.exit(not result.wasSuccessful())