Gracefully handle README-parsing failures

bin/app-json.py

@@ -137,6 +137,7 @@ def get_app_features(app_path):
         log.info(f"{app_path}/README.md")
         contents = handle.read()
 
+    try:
         for match in findall(r"\*\*.*\s\*", contents):
             title = search(r"(?<=\*\*).*(?=\*\*)", match).group().lower()
 
@@ -151,6 +152,11 @@ def get_app_features(app_path):
                 value = match.split(":")[-1].replace("*", "").strip()
 
             features[title] = value
+    except (IndexError, AttributeError):
+        log.info(f"Can't parse {app_path}/README.md")
+        return {}
+    finally:
+        _run_cmd("git checkout HEAD")
 
     log.info(f"Parsed {features}")