Add the tests to the command file

tests/test_command.py

@@ -0,0 +1,9 @@
+from unittest.mock import patch
+from pilgrim.command import main
+
+@patch('pilgrim.command.Application')
+def test_main_function_runs_application(MockApplication):
+    mock_app_instance = MockApplication.return_value
+    main()
+    MockApplication.assert_called_once()
+    mock_app_instance.run.assert_called_once()