destroy votes with their corresponding user

app/controllers/users_controller.rb

@@ -130,6 +130,9 @@ class UsersController < ApplicationController
   # DELETE /users/1
   # DELETE /users/1.json
   def destroy
+    Vote.where(user_id: @user.id).each do |vote|
+      vote.destroy
+    end
     @user.destroy
     respond_to do |format|
       format.html { redirect_to room_users_url(@user.room_id), notice: 'User was successfully destroyed.' }