new image for testing

.gitlab-ci.yml

 stages:
-  - py34
   - py35
   - py36
   - py37
-test-py3.4:
-  image: python:3.4
-  stage: py34
-  script:
-  - adduser --disabled-password --gecos '' myuser
-  - pip3 install -r requirements.txt
-  - python3.4 -m pytest --cov rpg tests
 test-py3.5:
   image: python:3.5
   stage: py35