Move deploy key enable/disable to the object

To keep things consistent with other objects, action methods are
available on the object itself, not the manager.

docs/gl_objects/deploy_keys.py

@@ -36,9 +36,9 @@
 # end delete
 
 # enable
-key = project.keys.enable(key_id)
+deploy_key.enable()
 # end enable
 
 # disable
-key = project.keys.disable(key_id)
+deploy_key.disable()
 # end disable

gitlab/objects.py

@@ -1249,21 +1249,21 @@ class ProjectKey(GitlabObject):
     requiredUrlAttrs = ['project_id']
     requiredCreateAttrs = ['title', 'key']
 
-
-class ProjectKeyManager(BaseManager):
-    obj_cls = ProjectKey
-
-    def enable(self, key_id):
+    def enable(self):
         """Enable a deploy key for a project."""
-        url = '/projects/%s/deploy_keys/%s/enable' % (self.parent.id, key_id)
+        url = '/projects/%s/deploy_keys/%s/enable' % (self.project_id, self.id)
         r = self.gitlab._raw_post(url)
         raise_error_from_response(r, GitlabProjectDeployKeyError, 201)
 
-    def disable(self, key_id):
+    def disable(self):
         """Disable a deploy key for a project."""
-        url = '/projects/%s/deploy_keys/%s/disable' % (self.parent.id, key_id)
+        url = '/projects/%s/deploy_keys/%s/disable' % (self.project_id, self.id)
         r = self.gitlab._raw_delete(url)
-        raise_error_from_response(r, GitlabProjectDeployKeyError, 201)
+        raise_error_from_response(r, GitlabProjectDeployKeyError, 200)
+
+
+class ProjectKeyManager(BaseManager):
+    obj_cls = ProjectKey
 
 
 class ProjectEvent(GitlabObject):