Add pytest to project

Add some plumbing for pytest

.gitignore

@@ -74,6 +74,9 @@ zesje/static/
 __pycache__/
 *.pyc
 
+# pytest temporary files
+.pytest_cache/
+
 # vscode folder
 .vscode
 

pytest.ini

+[pytest]
+testpaths = tests

tests/conftest.py

+import os
+
+import pytest
+
+
+# Adapted from https://stackoverflow.com/a/46062148/1062698
+@pytest.fixture
+def datadir():
+    return os.path.join(os.path.dirname(os.path.abspath(__file__)), 'data')