add requirement check to install script

install.sh

@@ -32,6 +32,14 @@ case $KERNEL in
     ;;
 esac
 
+for req in curl wget; do
+  command_exists $req || {
+    output "missing required $req binary"
+    req_failed=1
+  }
+done
+[ "$req_failed" == 1 ] && exit 1
+
 sh_c='sh -c'
 if [ "$CURRENT_USER" != 'root' ]; then
   if command_exists sudo; then