Add absolute_import future imports

Add absolute_import from __future__ so that pylint
does not fail and to achieve python3 behavior in
python2.

Reviewed-By: Christian Heimes <cheimes@redhat.com>
Reviewed-By: Alexander Bokovoy <abokovoy@redhat.com>

ipapython/kernel_keyring.py

@@ -17,6 +17,8 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #
 
+from __future__ import absolute_import
+
 import os
 import six