message: Add unauthorized() helper
diff: @@ -80,6 +80,11 @@ pub fn dyn_contract<T>(msg: String) -> Result<T> {
  DynContractErr { msg }.fail()
  }
  +pub fn unauthorized<T>() -> Result<T> {
  + Unauthorized { }.fail()
  +}
  +
  +
  #[cfg(test)]
  mod test {
  use super::*;
  