Add read_only parameter to Key schema

pygithub3/requests/issues/__init__.py

@@ -39,6 +39,6 @@ class Update(Request):
     resource = Issue
     body_schema = {
         'schema': ('title', 'body', 'assignee', 'state', 'milestone',
-                   'lables'),
+                   'labels'),
         'required': ()
     }

pygithub3/requests/repos/keys.py

@@ -23,7 +23,7 @@ class Create(Request):
     uri = 'repos/{user}/{repo}/keys'
     resource = Key
     body_schema = {
-        'schema': ('title', 'key'),
+        'schema': ('title', 'key', 'read_only'),
         'required': ('title', 'key')
     }