message: Remove expect on utf8
  Should always be utf8 in practice, but there's no point in panicking.
diff: use postgres_shared::rows::RowData;
  use std::fmt;
  use std::slice;
  +use std::str;
  #[doc(inline)]
  pub use postgres_shared::rows::RowIndex;
  @@ -171,7 +172,7 @@ impl<'a> TextRow<'a> {
  None => return None,
  };
  - // TODO can we assume these values will always be utf8?
  - Some(self.data.get(idx).map(|s| ::std::str::from_utf8(s).expect("utf8 encoded")))
  + self.data.get(idx)
  + .map(|s| str::from_utf8(s).ok())
  }
  }
  