[gnome-break-timer] Tell gitlab to build with the gnome:master image

[Dylan McCall <dylanmccall src gnome org>]

commit 7f88a87ad9fb1d7e83540682a8ed23cf821129cf
Author: Dylan McCall <dylan dylanmccall ca>
Date:   Tue Nov 24 16:37:17 2020 -0800

    Tell gitlab to build with the gnome:master image

 .gitlab-ci.yml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 27947c8..e8a21d0 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -6,7 +6,7 @@ variables:
 
 flatpak:
     extends: ['.flatpak']
-    image: registry.gitlab.gnome.org/gnome/gnome-runtime-images/gnome:3.38
+    image: registry.gitlab.gnome.org/gnome/gnome-runtime-images/gnome:master
     variables:
         APP_ID: "org.gnome.BreakTimer.Devel"
         MANIFEST_PATH: "build-aux/flatpak/org.gnome.BreakTimer.Devel.json"