add pypi workflow

.github/workflows/PyPI.yaml

@@ -0,0 +1,73 @@
+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
+  push:
+    branches:
+      - "main"
+  pull_request:
+    branches:
+      - "main"
+  schedule:
+    # Weekly tests run on main by default:
+    #   Scheduled workflows run on the latest commit on the default or base branch.
+    #   (from https://help.github.com/en/actions/reference/events-that-trigger-workflows#scheduled-events-schedule)
+    - cron: "0 0 * * 0"
+
+jobs:
+  test:
+    name: Test on ${{ matrix.os }}, Python ${{ matrix.python-version }}
+    runs-on: ${{ matrix.os }}
+    strategy:
+      matrix:
+        # os: [macOS-latest, ubuntu-latest, windows-latest]      # TODO use this when macOS-latest becomes stable again
+        os: [macOS-13, ubuntu-latest, windows-latest]
+        python-version: [3.8, 3.9, "3.10"]
+
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+
+      - name: Checkout latest tag
+        shell: bash
+        run: |
+          TAG=`git describe --tags $(git rev-list --tags --max-count=1)`
+          git checkout tags/$TAG
+
+      - name: Additional info about the build
+        shell: bash
+        run: |
+          uname -a
+          df -h
+          ulimit -a
+
+      - name: Install package from PyPI
+        # conda setup requires this special shell
+        shell: bash -l {0}
+        run: |
+          python -m pip install mlcolvar
+          micromamba list
+
+      - name: Run tests
+        # conda setup requires this special shell
+        shell: bash -l {0}
+        run: |
+          pytest -v --cov=mlcolvar --cov-report=xml --color=yes mlcolvar/tests/
+
+      - name: Run notebook tests
+        # conda setup requires this special shell
+        shell: bash -l {0}
+        if: contains( matrix.os, 'ubuntu' )
+        run: |
+          pytest -v --nbmake docs/notebooks/ --ignore=docs/notebooks/tutorials/data/ --cov=mlcolvar --cov-append --cov-report=xml --color=yes 
+
+      - name: CodeCov
+        if: contains( matrix.os, 'ubuntu' )
+        uses: codecov/codecov-action@v3
+        with:
+          token: ${{ secrets.CODECOV_TOKEN }}
+          file: ./coverage.xml
+          flags: codecov
+          name: codecov-${{ matrix.os }}-py${{ matrix.python-version }}