Refactor and optimise some tests (#245)

* Rename to follow actual directory name

* Remove unnecessary Reddit call from test

* Refactor test to reduce duplication

* Parameterise some tests

* Standardise formatting

bulkredditdownloader/tests/test_configuration.py

@@ -10,7 +10,10 @@ from bulkredditdownloader.configuration import Configuration
 
 @pytest.mark.parametrize('arg_dict', (
     {'directory': 'test_dir'},
-    {'directory': 'test_dir', 'no_dupes': True},
+    {
+        'directory': 'test_dir',
+        'no_dupes': True,
+    },
 ))
 def test_process_click_context(arg_dict: dict):
     test_config = Configuration()