tre panics on non-UTF8 filenames

[sp1ff]

Just installed your tool & looking forward to using it.

I'm running Arch Linux, with LANG set to en_US.UTF-8. I happen to have in my directory a file with a non-UTF8 filename. I realize that, given my environment, this would be considered unexpected. Ironically, I constructed it to trouble-shoot a bug regarding non-UTF8 filenames in one of my projects.

That said, when I run tre I am told:

thread 'main' (1581847) panicked at /home/mgh/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/tre-0.1.1/src/streamer.rs:60:67:
called `Result::unwrap()` on an `Err` value: "zo\xE8.mp3"
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace

Which seems to me not a great UX. FWIW, a simple ls displays:

'zo'$'\350''.mp3'

You might consider rendering unexpected filenames something like that?