[meld/flatpak-ci] Add review and nightly configuration for flatpak builds

[Kai Willadsen <kaiw src gnome org>]

commit 0dfbeec57edf13a23f14817752ab3d0f6e2a9766
Author: Kai Willadsen <kai willadsen gmail com>
Date:   Mon Oct 7 09:01:54 2019 +1000

    Add review and nightly configuration for flatpak builds
    
    This has been taken wholesale from
    https://gitlab.gnome.org/GNOME/Initiatives/wikis/DevOps-with-Flatpak
    and will almost certainly not work right without some additional
    application ID handling.

 .gitlab-ci.yml | 15 +++++++++++++++
 1 file changed, 15 insertions(+)
---
diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index efcf45bb..779a693d 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -28,6 +28,21 @@ flatpak:
         APP_ID: "org.gnome.Meld"
     extends: .flatpak
 
+review:
+    stage: deploy
+    dependencies:
+        - 'flatpak'
+    extends: '.review'
+
+stop_review:
+    stage: deploy
+    extends: '.stop_review'
+
+nightly:
+  extends: '.publish_nightly'
+  dependencies:
+    - 'flatpak'
+
 lint:
   stage: check
   script: