setUsername refactor

client/coral-framework/graphql/fragments.js

@@ -3,6 +3,7 @@ import {createDefaultResponseFragments} from '../utils';
 // fragments defined here are automatically registered.
 export default {
   ...createDefaultResponseFragments(
+    'SetUsernameResponse',
     'SetUserBanStatusResponse',
     'SetUserSuspensionStatusResponse',
     'SetCommentStatusResponse',

client/coral-framework/graphql/mutations.js

@@ -198,7 +198,7 @@ export const withRejectUsername = withMutation(
 
 export const withSetUsername = withMutation(
   gql`
-    mutation RejectUsername($id: ID!, $username: String) {
+    mutation RejectUsername($id: ID!, $username: String!) {
       setUsername(id: $id, username: $username) {
         ...SetUsernameResponse
       }