Change docker img

.gitlab-ci.yml

-image: python:3.9
+image: clarinpl/python:3.8
 
 variables:
   PIP_CACHE_DIR: "$CI_PROJECT_DIR/.cache/pip"
@@ -13,10 +13,12 @@ stages:
   - publish
 
 before_script:
-  - python --version ; pip --version  # For debugging
-  - pip install virtualenv
-  - virtualenv venv
-  - source venv/bin/activate
+  - apt-get update -yqq
+    && apt-get install -yqq --no-install-recommends
+    make
+    g++
+    && apt-get autoremove -yqq --purge
+    && apt-get clean
 
 pypi_publish:
   before_script: