[gnome-games] meson: Bump retro-gtk version to 0.18.0

[Alexander Mikhaylenko <alexm src gnome org>]

commit 4fcd25adbcbee735b856b6578beb36358e8f5e2b
Author: Alexander Mikhaylenko <exalm7659 gmail com>
Date:   Thu Sep 12 00:07:51 2019 +0500

    meson: Bump retro-gtk version to 0.18.0

 meson.build | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/meson.build b/meson.build
index 919504ca..54d664a1 100644
--- a/meson.build
+++ b/meson.build
@@ -30,7 +30,7 @@ valac = meson.get_compiler ('vala')
 
 glib_min_version = '2.38'
 manette_min_version = '0.2.0'
-retro_gtk_min_version = '0.15.3'
+retro_gtk_min_version = '0.18.0'
 handy_min_version = '0.0.10'
 
 archive_dep = dependency ('libarchive')