Prevent running keys.sh with no params

keys.sh

@@ -4,6 +4,11 @@
 # Utility script for generating a private/public key pair
 #
 
+if [[ -z "$1" ]]; then
+	echo "usage: ./keys.sh [key_basename]"
+	exit 1
+fi
+
 mkdir keys
 
 openssl genrsa -out keys/$1 2048