error: use of deprecated associated function `std::error::Error::description`: use the Display impl or to_string()
  --> src/error.rs:25:41
   |
25 |             IoError(ref error) => error.description(),
   |                                         ^^^^^^^^^^^
   |
note: the lint level is defined here
  --> src/lib.rs:72:9
   |
72 | #![deny(warnings, missing_debug_implementations, missing_copy_implementations, missing_docs)]
   |         ^^^^^^^^
   = note: `#[deny(deprecated)]` implied by `#[deny(warnings)]`