Doesn't work on Sketch 3.5
After typing in commit message or when trying to generate pretty diffs, I receive the following error:

`2016-01-27 12:43:17.856 sketchtool[31862:11553973] Error: caught exception whilst suppressing update events: *** -[MSUnarchiver decodeObjectForKey:]: cannot decode object of class (MSImmutableSharedStyleContainer) for key (layerStyles); the class may be defined in source code or a library that is not linked
2016-01-27 12:43:17.857 sketchtool[31862:11553973] Error: caught exception whilst decoding (version 76):*** -[MSUnarchiver decodeObjectForKey:]: cannot decode object of class (MSImmutableSharedStyleContainer) for key (layerStyles); the class may be defined in source code or a library that is not linked
Failed to open document Playlist.sketch -- file:///Users/danross/design-android/
((null) MSDocumentDomain:11)`
