fixed spaces in download URLs

So some songs have spaces in their URL, which causes great sadness:

    ❯ ruby get-hyped.rb popular
    Using target directory: mp3
    Downloading: Potato Potato - You Can Find What You're Looking For
       - http://go.hillydilly.com/hd_uploads/songs/downloadmusic.php?file=You Can Find mp3.mp3
       [ERROR] Couldn't download Potato Potato - You Can Find What You're Looking For
    Complete! Parsed 20, Downloaded 0

This patch decreases overall sadness substantially

    ❯ ruby get-hyped.rb popular
    Using target directory: mp3
    Downloading: Potato Potato - You Can Find What You're Looking For
       - http://go.hillydilly.com/hd_uploads/songs/downloadmusic.php?file=You%20Can%20Find%20mp3.mp3
       Success!
    Complete! Parsed 20, Downloaded 1