Use our image with go from stretch-backports

.gitlab-ci.yml

@@ -3,10 +3,9 @@ stages:
 
 build:
   stage: build
-  image: "ai/build:stretch"
+  image: "ai/test:go"
   script:
-    - env DEBIAN_FRONTEND=noninteractive apt-get -qy install golang
-    - mkdir build/git.autistici.org/ai3
+    - mkdir -p build/git.autistici.org/ai3
     - ln -s $PWD build/git.autistici.org/ai3/float-debug-proxy
     - env GOPATH=$PWD/build go build -o float-debug-proxy git.autistici.org/ai3/float-debug-proxy
   artifacts: