Option `--fg`  Not Working

`--fg` is not working: tried on 1.1.1 (which gave me `dotify` is not a function error), and then on 1.3.2 (latest).

Here's the standard output message on 1.3.2:
```
╰─$ js-callgraph --fg app.js                   
eval => Prop(eval)
parseInt => Prop(parseInt)
parseFloat => Prop(parseFloat)
isNaN => Prop(isNaN)
isFinite => Prop(isFinite)
decodeURI => Prop(decodeURI)
...
```