matrix support landed in gitlab, try it out

  - apt update && apt install -y python3-dev

  - python setup.py build

# GitLab CI doesn't support build matrices, yet:

#

# https://gitlab.com/gitlab-org/gitlab/issues/15356

#

# So we use a job template to avoid mindless repetition.  All of our

# jobs run 'tox', and we vary which tox environment they run or which

# We use a job template to avoid mindless repetition.  All of our jobs

# run 'tox', and we vary which tox environment they run or which

# Python version they use by overriding the 'TOXENV' environment

# variable or the 'image' job parameter.

#

    # which allows us to test various Python versions by changing the

    # Docker image version in use.

# match this list of python versions with the classifiers variable in

# setup.py. see also the list in .gitlab-ci.yml, which is specific to

# the docker container running the tests

test-3.5:

  extends: .tox

  image: python:3.5

test-3.6:

  extends: .tox

  image: python:3.6

test-3.7:

  extends: .tox

  image: python:3.7

test-3.8:

# the main test suite, for each python version

test:

  extends: .tox

  image: python:3.8

  # match this list of python versions with the classifiers variable

  # in setup.py. see also the list in .gitlab-ci.yml, which is

  # specific to the docker container running the tests

  parallel:

    matrix:

      - IMAGE:

          - python:3.5

          - python:3.6

          - python:3.7

          - python:3.8

  image: $IMAGE

flake8:

  extends: .tox