word-count: Use &[T] instead of &Vec<T>
word-count: Use &[T] instead of &Vec<T>

Clippy suggested:
this argument is passed by value, but not consumed in the function body

https://rust-lang-nursery.github.io/rust-clippy/master/index.html#needless_pass_by_value

petertseng/exercism-rust,exercism/xrust,petertseng/exercism-rust,exercism/xrust,petertseng/exercism-rust