Python code modernization, 3/n (#1157)

* Remove __metaclass__ = type.

for i in $(grep -REl '__metaclass__ = type' plugins/ tests/); do
  sed -e '/^__metaclass__ = type/d' -i $i;
done

* Remove super arguments, and stop inheriting from object.

plugins/inventory/docker_containers.py

@@ -386,7 +386,7 @@ class InventoryModule(BaseInventoryPlugin, Constructable):
 
     def verify_file(self, path):
         """Return the possibly of a file being consumable by this plugin."""
-        return super(InventoryModule, self).verify_file(path) and path.endswith(
+        return super().verify_file(path) and path.endswith(
             ("docker.yaml", "docker.yml")
         )
 
@@ -394,7 +394,7 @@ class InventoryModule(BaseInventoryPlugin, Constructable):
         return AnsibleDockerClient(self, min_docker_api_version=MIN_DOCKER_API)
 
     def parse(self, inventory, loader, path, cache=True):
-        super(InventoryModule, self).parse(inventory, loader, path, cache)
+        super().parse(inventory, loader, path, cache)
         self._read_config_data(path)
         client = self._create_client()
         try:

plugins/inventory/docker_machine.py

@@ -326,11 +326,11 @@ class InventoryModule(BaseInventoryPlugin, Constructable, Cacheable):
 
     def verify_file(self, path):
         """Return the possibility of a file being consumable by this plugin."""
-        return super(InventoryModule, self).verify_file(path) and path.endswith(
+        return super().verify_file(path) and path.endswith(
             ("docker_machine.yaml", "docker_machine.yml")
         )
 
     def parse(self, inventory, loader, path, cache=True):
-        super(InventoryModule, self).parse(inventory, loader, path, cache)
+        super().parse(inventory, loader, path, cache)
         self._read_config_data(path)
         self._populate()

plugins/inventory/docker_swarm.py

@@ -308,7 +308,7 @@ class InventoryModule(BaseInventoryPlugin, Constructable):
 
     def verify_file(self, path):
         """Return the possibly of a file being consumable by this plugin."""
-        return super(InventoryModule, self).verify_file(path) and path.endswith(
+        return super().verify_file(path) and path.endswith(
             ("docker_swarm.yaml", "docker_swarm.yml")
         )
 
@@ -318,6 +318,6 @@ class InventoryModule(BaseInventoryPlugin, Constructable):
                 "The Docker swarm dynamic inventory plugin requires the Docker SDK for Python: "
                 "https://github.com/docker/docker-py."
             )
-        super(InventoryModule, self).parse(inventory, loader, path, cache)
+        super().parse(inventory, loader, path, cache)
         self._read_config_data(path)
         self._populate()