Revert "Do not require requests-kerberos for tests"

This reverts commit 1946ed303b.

Change-Id: If4b1db131af467eb9a0910584c0fdc08dcee10c6

test-requirements.txt

@@ -6,6 +6,7 @@ mock<1.1
 unittest2
 python-subunit
 requests-mock>=1.4.0
+requests-kerberos
 sphinx>=1.2,<1.3.0
 stestr>=2.0.0
 testscenarios

tests/base.py

@@ -24,6 +24,8 @@ class JenkinsTestBase(TestWithScenarios, unittest.TestCase):
 
     def setUp(self):
         super(JenkinsTestBase, self).setUp()
+        # TODO(darragh) would be useful if this could be mocked
+        jenkins.requests_kerberos = None
 
         self.j = jenkins.Jenkins(self.base_url, 'test', 'test')