Fix, only parse valid JSON files

lib/combine.py

@@ -15,6 +15,7 @@ templates = []
 for file in files:
     # Open the file
     with open(templates_src_dir + file) as f:
+        if file.endswith('.json'):
           # Load the JSON into a variable
           data = json.load(f)['templates']
           # Append the template object to the templates list