Address some pylint issues (#1155)

* Address cyclic-import.

* Address redefined-builtin.

* Address redefined-argument-from-local.

* Address many redefined-outer-name.

* Address pointless-string-statement.

* No longer needed due to separate bugfix.

* Address useless-return.

* Address possibly-used-before-assignment.

* Add TODOs.

* Address super-init-not-called.

* Address function-redefined.

* Address unspecified-encoding.

* Clean up more imports.

plugins/modules/docker_swarm.py

@@ -504,7 +504,7 @@ class SwarmManager(DockerBaseClass):
             unlock_key = self.get_unlock_key()
             self.swarm_info.update(unlock_key)
         except APIError:
-            return
+            pass
 
     def get_unlock_key(self):
         default = {"UnlockKey": None}