mir_eval from nixpkgs example shell

shell.nix

{ pkgs ? import <nixpkgs> { } }:
pkgs.mkShell {
  packages = [
    (pkgs.python3.withPackages (ps: with ps; [
      ipython
      mir_eval
    ]))
  ];
  shellHook = ''
    ipython -c 'import mir_eval; print(mir_eval.__version__)'
  '';
}