ci: use conda-devenv to build environment.yml for tests

.github/workflows/run_pytests.yaml

@@ -21,18 +21,24 @@ jobs:
             python-version: 3.6
     steps:
     - uses: actions/checkout@v1
+    - name: Create the environment.yml via conda-devenv
+      run: |
+        python -m pip install --upgrade pip
+        pip install --upgrade setuptools
+        pip install git+https://github.com/ESSS/conda-devenv.git@v2.1.1
+        conda-devenv --file environment.devenv.yml --print > environment.yml
     - name: Cache conda
       uses: actions/cache@v1
       env:
         # Increase this value to reset cache if etc/example-environment.yml has not changed
         CACHE_NUMBER: 0
       with:
         path: ~/conda_pkgs_dir
-        key: ${{ runner.os }}-conda-${{ env.CACHE_NUMBER }}-${{ hashFiles('environment.yaml') }}
+        key: ${{ runner.os }}-conda-${{ env.CACHE_NUMBER }}-${{ hashFiles('environment.yml') }}
     - name: Setup conda
       uses: goanpeca/setup-miniconda@v1
       with:
-        environment-file: environment.yaml
+        environment-file: environment.yml
         python-version: ${{ matrix.python-version }}
         auto-update-conda: true
         activate-environment: paquo