Panic

I was trying to use this tool and it doesn't seem to support arguments given in a file.

Here is a small example:

$ cargo install --git https://gitlab.redox-os.org/redox-os/parallel.git
$ for i in {0..10} ; echo $i >> input.lst ; done
$ parallelion 'echo {}' -a input.lst
thread 'main' panicked at 'called `Result::unwrap()` on an `Err` value: "SendError(..)"', src/main.rs:110:34