add unit tests workflow

.github/workflows/tests.yml

@@ -0,0 +1,21 @@
+name: Run Unit Tests
+
+on: [push]
+
+jobs:
+  build:
+    runs-on: ubuntu-20.04
+
+    steps:
+    - uses: actions/checkout@v3
+    - name: Set up Python 2.7
+      uses: actions/setup-python@v4
+      with:
+        python-version: 2.7
+    - name: Install dependencies
+      run: |
+        python -m pip install --upgrade pip
+        pip install -e . -r ./requirements/dev
+    - name: Launch tests
+      run: |
+        nosetests ./tests