Update .gitlab-ci.yml file to follow example by Duncan

Duncan has kindly provided some template .gitlab-ci.yml file example for use in pyDARM using some new templates he has set up. I copy and paste the example he provided, in the case that we lose access to his example file. We may wish to bring this in at an opportune moment perhaps in between major merge requests.

# include templates from gitlab-ci-templates
# for docs see https://computing.docs.ligo.org/gitlab-ci-templates
include:
  - project: computing/gitlab-ci-templates
    file:
      - /conda/base.yml
      - /python/lint.yml
      - /python/test.yml

stages:
  - test
  - lint

# ---------------------------
# lint the code with flake8
# using the job template from
# .python:flake8
# ---------------------------
lint:
  extends:
    # https://computing.docs.ligo.org/gitlab-ci-templates/python/#pythonflake8
    - .python:flake8
  stage: lint
  needs: []

python3:
  extends:
    # extend from the conda:base job to get default conda configuration
    # https://computing.docs.ligo.org/gitlab-ci-templates/conda/#.conda:base
    - .conda:base
  image: igwn/base:conda
  stage: test
  needs: []
  before_script:
    # run the `before_script` block from the conda:base template
    - !reference [".conda:base", before_script]
    # create a conda environment to run the tests in
    - conda create --name pydarm-test
          coverage
          numpy
          pip
          python=3
          scipy
    - conda activate pydarm-test
    - python -m pip install
          dttxml
  script:
    - conda activate pydarm-test  # just in case
    # run unittests with coverage
    - python3 -m coverage run --source=pydarm
          -m unittest discover
    # test the CLIs
    - python3 -m coverage run --append --source=pydarm
          -m pydarm --help
    - python3 -m coverage run --append --source=pydarm
          -m pydarm fr --help
  after_script:
    # print coverage report
    - export PYTHON="${CONDA_ENVS_PATH}/pydarm-test/bin/python3"
    - !reference [".python:pytest", after_script]
    # clean the conda cache
    - !reference [".conda:cache", after_script]
  # parse the coverage total from the report
  coverage: '/^TOTAL\s+.*\s+(\d+\.?\d*)%/'