= Improvements

* rotp 5.1 is now supported in the otp feature.  Previous rotp
  versions down to rotp 2.1.1 remain supported.

* When using the otp feature without the sms or recovery_codes
  features, if an account gets locked out from OTP authentication due
  to multiple invalid OTP authentication codes, automatically log
  them out, and redirect them to the login page.  Previously, the
  default behavior in this case could be a redirect loop if OTP
  authentication is required for the user on the default_redirect
  page.