Rename 'all' metascope to more descriptive 'inherit'

since it means 'inheriting' the owner's permissions

'all' prompted the question 'all of what, exactly?'

Additionally, fix some NameErrors that should have been KeyErrors

jupyterhub/apihandlers/users.py

@@ -397,9 +397,11 @@ class UserTokenListAPIHandler(APIHandler):
         token_roles = body.get('roles')
         try:
             api_token = user.new_api_token(
-                note=note, expires_in=body.get('expires_in', None), roles=token_roles
+                note=note,
+                expires_in=body.get('expires_in', None),
+                roles=token_roles,
             )
-        except NameError:
+        except KeyError:
             raise web.HTTPError(404, "Requested roles %r not found" % token_roles)
         except ValueError:
             raise web.HTTPError(