Merge branch '85-collapse-not-working' into 'master'

Resolve "collapse not working"

Closes #85

See merge request troebs/pycs!77

pycs/ApplicationStatus.py

@@ -27,6 +27,6 @@ class ApplicationStatus(ObservableDict):
         # subscribe to settings change to write it to file
         self['settings'].subscribe(self.__write_settings_to_file)
 
-    def __write_settings_to_file(self, settings):
+    def __write_settings_to_file(self, settings, keys):
         with open(self.__path_to_settings_json, 'w') as settings_json:
             dump(settings, settings_json, indent=4)