try using python:3-stretch image in ci

.gitlab-ci.yml

-before_script:
-    - apt update
-    - apt install -y python3
-    - python3 -V
-    - uname -a
-
 unittest:
-    image: debian:stretch
+    image: python:3-stretch
     stage: test
     script:
+    - apt update
+    - python3 -V
+    - uname -a
     - apt install -y sqlite3 locales-all git python3-flask python3-ldap3 python3-requests python3-lxml python3-icalendar python3-mysql.connector python3-requests python3-coverage
     - python3 -m coverage run tests.py
     - python3 -m coverage report --include "./*"
@@ -20,8 +17,18 @@ unittest:
         - report.txt
 
 livetest:
-    image: debian:stretch
+    image: python:3-stretch
     stage: test
     script:
+    - apt update
+    - python3 -V
+    - uname -a
     - apt install -y python3-requests
-    - ./tests/urlcheck_sinf.py
\ No newline at end of file
+    - ./tests/urlcheck_sinf.py
+
+deploytotest:
+    image: archlinux
+    stage: deploy
+    script:
+    - pacman -S ansible git
+    
\ No newline at end of file