added admin credential env vars for testing

tests/conftest.py

@@ -12,3 +12,9 @@ def pytest_configure(config: pytest.Config) -> None:
         tmpdir = tempfile.mkdtemp(prefix="baby_monitor_test_")
         os.environ["DATA_DIR"] = tmpdir
         os.environ["ENVIRONMENT"] = "development"
+
+    # Set admin credentials for tests
+    if "ADMIN_USERNAME" not in os.environ:
+        os.environ["ADMIN_USERNAME"] = "admin"
+    if "ADMIN_PASSWORD" not in os.environ:
+        os.environ["ADMIN_PASSWORD"] = "password"