add test + code coverage workflow

.github/workflows/code-coverage.yml

@@ -0,0 +1,30 @@
+name: push
+on: [push, pull_request]
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - uses: actions/setup-python@v5
+
+      - name: Install package
+        run: python -m pip install .
+
+      - name: Install coverage
+        run: python -m pip install coverage
+
+      - name: Unit tests
+        run: tests/run_tests.sh -c
+
+      - name: Coveralls
+        uses: coverallsapp/github-action@v2
+
+  coveralls_finish:
+    needs: test
+    runs-on: ubuntu-latest
+    steps:
+      - name: Coveralls Finished
+        uses: AndreMiras/coveralls-python-action@develop
+        with:
+          parallel-finished: true