Merge branch 'ci' into 'master'

ci

See merge request !1

.gitlab-ci.yml

+build:
+  image: omi-registry.e-technik.uni-ulm.de/sv/buildx:latest
+  stage: build
+  script:
+    - docker login -u "$CI_REGISTRY_USER" -p "$CI_REGISTRY_PASSWORD" $CI_REGISTRY
+    - docker buildx build --push --platform linux/arm64,linux/amd64 --tag "$CI_REGISTRY_IMAGE" .
+    - docker manifest inspect "$CI_REGISTRY_IMAGE"

Dockerfile

+FROM alpine
+
+RUN apk add -U curl