Move .gitlab-ci.yml to debian/salsa-ci.yml

This seems to be the standard location for Salsa's CI.

debian/salsa-ci.yml

@@ -0,0 +1,26 @@
+stages:
+  - build
+
+build:
+  retry:
+    max: 2
+    when: always
+  only:
+    - branches
+    - master # I suppose that we can work directly on master
+    - merge_request
+  stage: build
+  image: debian:sid
+  dependencies: []
+  script:
+    - apt-get update && apt-get install -y vmdb2 dosfstools qemu-utils qemu-user-static debootstrap binfmt-support time kpartx bmap-tools python3 fakemachine make
+    - make yaml
+    - mkdir build
+    - cp raspi*.yaml build
+  artifacts:
+    paths:
+      - build
+
+variables:
+  DEBIAN_FRONTEND: "noninteractive"
+