Set reset_password_sent_at to current time when emailing reset password token Fixes #107

See http://stackoverflow.com/questions/6853026/rails-devise-reset-password-token-keeps-getting-marked-as-expired for reasoning.
When overriding the devise send_password_reset_email function you need to set the time at which the token was sent.
Merge pull request #108 from tomwilshere/patch-1

Set reset_password_sent_at to current time when emailing reset password ...