Return 204 for delete endpoints

lib/api/members.rb

@@ -99,7 +99,7 @@ module API
         end
         delete ":id/members/:user_id" do
           source = find_source(source_type, params[:id])
-          # Ensure that memeber exists
+          # Ensure the member exists
           source.members.find_by!(user_id: params[:user_id])
 
           ::Members::DestroyService.new(source, current_user, declared_params).execute