[simple-scan] Enable snap creation during CI build

[Ken VanDine <kvandine src gnome org>]

commit 3335fb0e8477c7810c2184f8b69c0bdf16ddb9ad
Author: Bartosz Kosiorek <gang65 poczta onet pl>
Date:   Tue Apr 28 23:16:38 2020 +0200

    Enable snap creation during CI build

 .gitlab-ci.yml | 11 +++++++++++
 1 file changed, 11 insertions(+)
---
diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index aca8600..72d7ad5 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -1,3 +1,14 @@
+build:snap:
+  stage: build
+  image: ubuntudesktop/gnome-3-28-1804
+  before_script:
+    - apt-get update
+  script: snapcraft
+  allow_failure: true
+  artifacts:
+    paths: ['./*.snap']
+    expire_in: 3 days
+
 build-ubuntu:
   image: ubuntu:rolling
   before_script: