Remove broken test stage

.gitlab-ci.yml

 
 stages:
-  - test
   - build_pkgsrc
   - build_pkg
   - upload_pkg
 
-# Do not run tests on master, they are executed by the
-# Debian package builder.
-# TODO: currently broken
-test:
-  stage: test
-  image: "debian:stretch"
-  script:
-    - "./install_restic_for_tests.sh"
-    - "apt-get install -y liblz4-tool golang"
-    - "go test -v ./..."
-  except:
-    - master
-
 build_pkgsrc:stretch:
   stage: build_pkgsrc
   image: "registry.git.autistici.org/ai3/build-deb:stretch-amd64"