keep formatting consistent

catalog_reader/app.py

@@ -146,19 +146,21 @@ def get_app_details_impl(
 
     return item_data
 
+
 def new_line_to_space(text: str) -> str:
     return text.replace('\n', ' ')
 
+
 def get_app_version_details(
     version_path: str, questions_context: typing.Optional[dict], options: typing.Optional[dict] = None
 ) -> dict:
     options = options or {}
     version_data = {'location': version_path, 'required_features': set()}
     for key, filename, parser, post_processor in (
-        ("app_metadata", "app.yaml", yaml.safe_load, None),
-        ("schema", "questions.yaml", yaml.safe_load, None),
-        ("readme", "README.md", markdown.markdown, new_line_to_space),
-        ("changelog", "CHANGELOG.md", markdown.markdown, new_line_to_space),
+        ('app_metadata', 'app.yaml', yaml.safe_load, None),
+        ('schema', 'questions.yaml', yaml.safe_load, None),
+        ('readme', 'README.md', markdown.markdown, new_line_to_space),
+        ('changelog', 'CHANGELOG.md', markdown.markdown, new_line_to_space),
     ):
         if os.path.exists(os.path.join(version_path, filename)):
             with open(os.path.join(version_path, filename), 'r') as f: