Tests Cleanup: Fix missing calls to setUpClass/tearDownClass.

Continuation/Part 2 of https://gerrit.fd.io/r/#/c/17092/

Change-Id: Id0122d84eaf2c05d29e5be63a594d5e528ee7c9a
Signed-off-by: Paul Vinciguerra <pvinci@vinciconsulting.com>
diff --git a/test/test_pppoe.py b/test/test_pppoe.py
index b6a1eef..5c8495f 100644
--- a/test/test_pppoe.py
+++ b/test/test_pppoe.py
@@ -25,6 +25,10 @@
         cls.dst_ip = "100.1.1.100"
         cls.dst_ipn = socket.inet_pton(socket.AF_INET, cls.dst_ip)
 
+    @classmethod
+    def tearDownClass(cls):
+        super(TestPPPoE, cls).tearDownClass()
+
     def setUp(self):
         super(TestPPPoE, self).setUp()