[citemplates] Flatpak Template: Make warning fatal when running tests

[Jordan Petridis <jpetridis src gnome org>]

commit 07c596a85c6c2871c2c38b3477a44fddab5ff152
Author: Jordan Petridis <jpetridis gnome org>
Date:   Mon Dec 10 16:36:16 2018 +0200

    Flatpak Template: Make warning fatal when running tests

 flatpak/flatpak_ci_initiative.yml | 1 +
 1 file changed, 1 insertion(+)
---
diff --git a/flatpak/flatpak_ci_initiative.yml b/flatpak/flatpak_ci_initiative.yml
index 565e8cb..138493c 100644
--- a/flatpak/flatpak_ci_initiative.yml
+++ b/flatpak/flatpak_ci_initiative.yml
@@ -14,6 +14,7 @@
       flatpak build
       --env=LANG=C.UTF-8
       --env=NO_AT_BRIDGE=1
+      --env=G_DEBUG=fatal-warnings
       app
       dbus-run-session
       meson test -C _build --no-stdsplit --print-errorlogs