Add nmap command test.

check-cipher.sh

@@ -3,4 +3,5 @@ fqdn=$1
 port=${2:-443}
 [ -x $fqdn ] && echo "FQDN of the site is required." && exit 1
 ! host $fqdn > /dev/null && echo "$fqdn is not a vaild host." && exit 1
+! which nmap && echo "namp command is required." && exit 1
 nmap --script ssl-enum-ciphers -p 443 $fqdn