Switch ci to byzantium

.gitlab-ci.yml

@@ -5,6 +5,7 @@ variables:
              python3-requests
              python3-tqdm
              python3-yaml
+  IMAGE: pureos/byzantium
 
 .tags: &tags
   tags:
@@ -13,6 +14,7 @@ variables:
 build:deb:
   <<: *tags
   stage: build
+  image: $IMAGE
   before_script:
     - export DEBIAN_FRONTEND=noninteractive
     - apt-get -y update
@@ -28,6 +30,7 @@ build:deb:
 test:download:deb:
   <<: *tags
   stage: test
+  image: $IMAGE
   before_script:
     - export DEBIAN_FRONTEND=noninteractive
     - apt-get -y update
@@ -46,6 +49,7 @@ test:download:deb:
 test:download:pip:
   <<: *tags
   stage: test
+  image: $IMAGE
   before_script:
     - export DEBIAN_FRONTEND=noninteractive
     - apt-get -y update