Add parallel job using pymc3 from dev repo

.github/workflows/python-tests.yml

@@ -70,3 +70,34 @@ jobs:
     - name: Check coverage
       run: |
         diff-cover ./coverage.xml --compare-branch=origin/main --fail-under=100 --diff-range-notation '..'
+
+  python-tests-pymc3-dev:
+
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        python-version: [3.7]
+
+    steps:
+    - uses: actions/checkout@v2
+      with:
+        fetch-depth: 0
+    - name: Set up Python ${{ matrix.python-version }}
+      uses: actions/setup-python@v2
+      with:
+        python-version: ${{ matrix.python-version }}
+    - name: Install dependencies
+      run: |
+        python -m pip install --upgrade pip
+        if [ -f requirements.txt ]; then pip install -r requirements.txt; fi
+        pip uninstall pymc3
+        pip install git+https://github.com/pymc-devs/pymc3.git
+    - name: Test with pytest
+      run: |
+        pytest tests --cov=pymc3_hmm --cov-report=xml:./coverage.xml
+    - name: Fetch main for coverage diff
+      run: |
+        git fetch --no-tags --prune origin main
+    - name: Check coverage
+      run: |
+        diff-cover ./coverage.xml --compare-branch=origin/main --fail-under=100 --diff-range-notation '..'