Address lint errors

cluster/juju/layers/kubernetes-master/reactive/kubernetes_master.py

@@ -703,7 +703,7 @@ def ceph_storage(ceph_admin):
         cmd = ['kubectl', 'apply', '-f', '/tmp/ceph-secret.yaml']
         check_call(cmd)
         os.remove('/tmp/ceph-secret.yaml')
-    except:
+    except: # NOQA
         # the enlistment in kubernetes failed, return and prepare for re-exec
         return
 

cluster/juju/layers/kubernetes-worker/reactive/kubernetes_worker.py

@@ -37,7 +37,7 @@ from charms.kubernetes.flagmanager import FlagManager
 from charms.reactive.helpers import data_changed, any_file_changed
 from charms.templating.jinja2 import render
 
-from charmhelpers.core import hookenv, unitdata
+from charmhelpers.core import hookenv
 from charmhelpers.core.host import service_stop, service_restart
 from charmhelpers.contrib.charmsupport import nrpe