tests/ota_test.py: Allow stand-alone execution

Let's add a __main__ section to allow stand-alone execution via
	python3 ./tests/test_ota.py

Change-Id: Ic3940ac23c7ddc1013e21f41eae6076a11dfd4f4

tests/test_ota.py

@@ -299,3 +299,6 @@ class SmsOtaTestCase(OtaTestCase):
                 self.assertEqual(d.number_of_commands, t['response']['number_of_commands'])
                 self.assertEqual(d.last_status_word, t['response']['last_status_word'])
                 self.assertEqual(d.last_response_data, t['response']['last_response_data'])
+
+if __name__ == "__main__":
+	unittest.main()