Fix lint errors in juju kubernetes master and e2e charms

cluster/juju/layers/kubernetes-e2e/reactive/kubernetes_e2e.py

@@ -14,14 +14,11 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-import os
-
 from charms import layer
 from charms.layer import snap
 
 from charms.reactive import hook
 from charms.reactive import is_state
-from charms.reactive import remove_state
 from charms.reactive import set_state
 from charms.reactive import when
 from charms.reactive import when_not
@@ -30,7 +27,6 @@
 
 from shlex import split
 
-from subprocess import call
 from subprocess import check_call
 from subprocess import check_output
 

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

@@ -441,7 +441,6 @@ def addons_ready():
         return False
 
 
-
 @when('loadbalancer.available', 'certificates.ca.available',
       'certificates.client.cert.available')
 def loadbalancer_kubeconfig(loadbalancer, ca, client):

cluster/juju/layers/kubernetes-master/tox.ini

@@ -0,0 +1,12 @@
+[tox]
+skipsdist=True
+envlist = py34, py35
+skip_missing_interpreters = True
+
+[testenv]
+commands = py.test -v
+deps =
+    -r{toxinidir}/requirements.txt
+
+[flake8]
+exclude=docs