Add tests for GitHub actions

Author: Saoski

.github/workflows/python-package.yml

@@ -37,4 +37,4 @@ jobs:
         flake8 . --count --exit-zero --max-complexity=10 --max-line-length=127 --statistics
     - name: Test with pytest
       run: |
-        pytest
+        pytest tests/

.idea/.gitignore

@@ -0,0 +1,3 @@
+# tests/test_sample.py
+def test_example():
+    assert 1 + 1 == 2