title: Rails devise reset password token doesn't get clear
body: <p>I am using devise gem. Devise send reset password token in mail when user clicks on forget password link. User follow the link and reset his password by entering new password and confirm new password. </p>
  
  <p>When I follow the same mail link again, it again allow the user to reset password in the same way as above.</p>
  
  <p>Now, I want the reset password token to clear once it is used. So that when your follow the previously used send link from old mail, he must get message that "Invalid token"</p>
  
  <p>How can I do this?</p>
  
  <p>Thanks in advance.</p>