title: how to authenticate ROLE_USER and ROLE_ADMIN separately in fos userbundle
body: <p>I have made two different login section in my website, one for admin section and another for frontend users.</p>
  
  <p>When I logged into to frontend it logged in. The problem is that when i try to login the admin section it throws access denied error.</p>
  
  <p>Is it possible make two different login sessions so that both login session are independent of eachother</p>