Removes Vec allocation

[pwoolcoc]

It looks like you are allocating a Vec and then immediately turning it back into an iterator, you can skip the allocation and just use the env::args iterator directly

[van-sprundel]

Looks like OP is relatively new to Rust. Not trying to discourage at all, I think this project could lead to something interesting!

As for another big sore thumb, you don't need to return true in your check_if_dir function, just return the condition