ci: add GitHub Actions workflow for automated testing

Runs pytest on push/PR to master and develop across:
- OS: ubuntu-latest, macos-latest
- Python: 3.10, 3.11, 3.12

Uses miniforge/conda to install mdtraj and scientific stack reliably.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: daviddesancho

.github/workflows/ci.yml

@@ -0,0 +1,46 @@
+name: CI
+
+on:
+  push:
+    branches: [master, develop]
+  pull_request:
+    branches: [master, develop]
+
+jobs:
+  test:
+    name: Python ${{ matrix.python-version }} / ${{ matrix.os }}
+    runs-on: ${{ matrix.os }}
+
+    strategy:
+      fail-fast: false
+      matrix:
+        os: [ubuntu-latest, macos-latest]
+        python-version: ["3.10", "3.11", "3.12"]
+
+    defaults:
+      run:
+        shell: bash -l {0}
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+
+      - name: Set up conda (miniforge)
+        uses: conda-incubator/setup-miniconda@v3
+        with:
+          miniforge-version: latest
+          python-version: ${{ matrix.python-version }}
+          activate-environment: mastermsm-test
+          auto-activate-base: false
+
+      - name: Install dependencies
+        run: |
+          conda install -y -c conda-forge \
+            numpy scipy matplotlib networkx \
+            mdtraj scikit-learn
+          pip install -e .
+
+      - name: Run tests
+        run: |
+          pip install pytest
+          pytest mastermsm/test/ -v --tb=short