adds simple test that runs the main function

tests/test_main.py

@@ -0,0 +1,11 @@
+"""Testing that the main function actually loads.
+
+This ensures that all the dependencies actually load too.
+"""
+
+from flickr_download.flick_download import main
+
+
+def test_main() -> None:
+    """Loads the main function and expects an exit code of 1."""
+    assert main() == 1