Update open lib to make it compile on Redox OS

[willnode]

It was not working due to to old "open" crate. Redox OS reference is here.

error: open is not supported on this platform
  --> /root/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/open-1.7.1/src/lib.rs:84:1
   |
84 | compile_error!("open is not supported on this platform");
   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

[TheWaWaR]

Thanks!