Reset krbtpolicy when a unit test is finished

Kerberos ticket maximum life was being set to 1 hour which then
affected lifetime of Kerberos tickets returned by IPA server under
the test.

Make sure that the policy is reset before and after the unit test to
keep the IPA server settings clean and not to disrupt development
environment.

tests/test_xmlrpc/test_krbtpolicy.py

@@ -30,6 +30,7 @@ user1 = u'tuser1'
 class test_krbtpolicy(Declarative):
     cleanup_commands = [
         ('user_del', [user1], {}),
+        ('krbtpolicy_reset', [], {}),
     ]
 
     tests = [