PG::Error: ERROR: relation "users" does not exist

sorry for disturb you but i have a lot of question about this error. first this is my user_controller rspec file

require 'spec/spec_helper'

describe UserController do

it "create new user" do
    post "create"
    assigns[:users].should_not be_new_record
end
end

this is my UserController

 class UserController < ApplicationController
   def create
     @users = User.new
     if @users.save
       flash[:notice] = 'new user was successfully created.'
     else
       render :action => :new
     end
   end

   def new
     @user = User.new
   end
 end

and my routes.rb (i think the problem is here, excuse me but i`m new in this language)

Estaciones::Application.routes.draw do
  devise_for :users

  root :to => "home#index"
  resources :user
end

when i try to test my user_controller_rspec then i get this error

Failures:

1) UserController create new user
   Failure/Error: post "create"
   ActiveRecord::StatementInvalid:
     PG::Error: ERROR:  relation "users" does not exist
     LINE 4:              WHERE a.attrelid = '"users"'::regclass
                                             ^
     :             SELECT a.attname, format_type(a.atttypid, a.atttypmod), d.adsrc, a.attnotnull
                   FROM pg_attribute a LEFT JOIN pg_attrdef d
                     ON a.attrelid = d.adrelid AND a.attnum = d.adnum
                    WHERE a.attrelid = '"users"'::regclass
                    AND a.attnum > 0 AND NOT a.attisdropped
                  ORDER BY a.attnum
 # ./app/controllers/user_controller.rb:3:in `new'
 # ./app/controllers/user_controller.rb:3:in `create'
 # ./spec/controllers/user_controller_spec.rb:6

 Finished in 0.01722 seconds
 1 example, 1 failure

 Failed examples:

 rspec ./spec/controllers/user_controller_spec.rb:5 # UserController create new user

how i can fix it... thanks