revert changes in CI

.github/workflows/CI.yaml

@@ -2,12 +2,15 @@ name: CI
 
 on:
   # GitHub has started calling new repo's first branch "main" https://github.com/github/renaming
-  # The cookiecutter uses the "--initial-branch" flag when it runs git-init
+  # Existing codes likely still have "master" as the primary branch
+  # Both are tracked here to keep legacy and new codes working
   push:
     branches:
+      - "master"
       - "main"
   pull_request:
     branches:
+      - "master"
       - "main"
   schedule:
     # Weekly tests run on main by default:
@@ -22,10 +25,10 @@ jobs:
     strategy:
       matrix:
         os: [macOS-latest, ubuntu-latest, windows-latest]
-        python-version: [3.8, 3.9]
+        python-version: [3.7, 3.8, 3.9]
 
     steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v1
 
     - name: Additional info about the build
       shell: bash
@@ -34,25 +37,34 @@ jobs:
         df -h
         ulimit -a
 
-      # More info on options: https://github.com/marketplace/actions/provision-with-micromamba
-      - uses: mamba-org/provision-with-micromamba@main
-        with:
-          environment-file: devtools/conda-envs/test_env.yaml
-          environment-name: test
-          channels: conda-forge,defaults
-          extra-specs: |
-            python=${{ matrix.python-version }}
 
-      - name: Install package
-        # conda setup requires this special shell
-        shell: bash -l {0}
-        run: |
-          python -m pip install . --no-deps
-          micromamba list
+    # More info on options: https://github.com/conda-incubator/setup-miniconda
+    - uses: conda-incubator/setup-miniconda@v2
+      with:
+        python-version: ${{ matrix.python-version }}
+        environment-file: devtools/conda-envs/test_env.yaml
+
+        channels: conda-forge,defaults
+
+        activate-environment: test
+        auto-update-conda: false
+        auto-activate-base: false
+        show-channel-urls: true
+
+    - name: Install package
+
+      # conda setup requires this special shell
+      shell: bash -l {0}
+      run: |
+        python -m pip install . --no-deps
+        conda list
+
 
     - name: Run tests
+
       # conda setup requires this special shell
       shell: bash -l {0}
+
       run: |
         pytest -v --cov=mlcvs --cov-report=xml --color=yes mlcvs/tests/
 
@@ -61,4 +73,4 @@ jobs:
       with:
         file: ./coverage.xml
         flags: unittests
-        name: codecov-${{ matrix.os }}-py${{ matrix.python-version }}
+        name: codecov-${{ matrix.os }}-py${{ matrix.python-version }}