a-zA-Z0-9 passwords only
a-zA-Z0-9 passwords only

To fix https://github.com/digitalocean/do_user_scripts/issues/16
ntuer/do_user_scripts,salouha/do_user_scripts,nielsonsantana/do_user_scripts,Pandafuchs/do_user_scripts,nvg58/do_user_scripts,digitalocean/do_user_scripts,ciavashkh/do_user_scripts