title: Rails devise reset_password_token keeps getting marked as "expired"
body: <p>I'm trying to use devise's reset_password_token to force users to change their password when they log in for the first time, using what I read here: <a href="https://stackoverflow.com/questions/5894191/rails-devise-set-password-reset-token-and-redirect-user">Rails Devise: Set password reset token and redirect user</a></p>
  
  <p>I get as far as a page loading that says "set your password", but every time I hit submit, there's a notice that says that the reset_password_token has expired and to request a new one. I've tried setting reset_password_token to a variable instead of accessing via the user object (@user.reset_password_token), in case expiration is calculated by if that token was accessed, but it still says it's expired when I try to set my initial password.  I'm not sure how expiration is calculated, anybody have an idea?  </p>