Unpin flake8, fix lint

Change-Id: I0c3a4b4f8291e0b19d131269554e09346754e120

hooks/neutron_hooks.py

@@ -155,7 +155,7 @@ def config_changed():
             for module in module_settings.split():
                 try:
                     modprobe(module)
-                except:
+                except Exception:
                     message = "Failed to load kernel module '%s'" % module
                     log(message, level=WARNING)
 

hooks/neutron_utils.py

@@ -1134,7 +1134,7 @@ def check_optional_relations(configs):
     if relation_ids('ha'):
         try:
             get_hacluster_config()
-        except:
+        except Exception:
             return ('blocked',
                     'hacluster missing configuration: '
                     'vip, vip_iface, vip_cidr')

test-requirements.txt

@@ -10,7 +10,7 @@
 charm-tools>=2.4.4
 requests>=2.18.4
 mock>=1.2
-flake8>=2.2.4,<=2.4.1
+flake8>=2.2.4
 stestr>=2.2.0
 coverage>=4.5.2
 pyudev              # for ceph-* charm unit tests (need to fix the ceph-* charm unit tests/mocking)

tox.ini

@@ -116,5 +116,5 @@ commands =
     functest-run-suite --keep-model --bundle {posargs}
 
 [flake8]
-ignore = E402,E226
+ignore = E402,E226,W504
 exclude = */charmhelpers