[gnome-control-center] Bump version to 3.31.0

[Georges Basile Stavracas Neto <gbsneto src gnome org>]

commit 78495e03dc9ab569bd3a925c3b4fe1a530395ac2
Author: Georges Basile Stavracas Neto <georges stavracas gmail com>
Date:   Fri Sep 7 22:52:14 2018 -0300

    Bump version to 3.31.0
    
    Let's branch now and allow some UI changes land.

 meson.build | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/meson.build b/meson.build
index 1dd93bf7f..49816d185 100644
--- a/meson.build
+++ b/meson.build
@@ -1,6 +1,6 @@
 project(
   'gnome-control-center', 'c',
-        version : '3.30.0',
+        version : '3.31.0',
         license : 'GPL2+',
   meson_version : '>= 0.43.0'
 )