remove python 2.6 trove classifier
remove python 2.6 trove classifier

OpenStack projects are no longer being tested under Python 2.6, so
remove the trove classifier implying that this project supports 2.6.

Change-Id: I1a8329a5c2c90900410dd4f48318b644edd9edc2

stackforge/monasca-ui,openstack/monasca-ui,stackforge/monasca-ui,stackforge/monasca-ui,stackforge/monasca-ui,openstack/monasca-ui,openstack/monasca-ui,openstack/monasca-ui