Force using version 3.6 of python because of inconsistent python symlinks

.gitlab-ci.yml

@@ -23,14 +23,14 @@ stages:
 
 push_wheel:
   before_script:
-   - pip install twine
+   - pip3.6 install twine
   only:
    - master
   stage: push_wheel
   when: on_success
   script:
-   - python setup.py sdist bdist_wheel
-   - python -m twine upload 
+   - python3.6 setup.py sdist bdist_wheel
+   - python3.6 -m twine upload 
      --repository-url https://pypi.clarin-pl.eu/
      -u $PIPY_USER -p $PIPY_PASS dist/cclutils*.whl