When labels contain a full stop/period, they should be wrapped in quotes in output

[Ruxton]

I set a node label to a string with a . in it.

The graphviz output did not wrap the label in quotes.

Should be label="thing.name" but is label=thing.name

[icco]

I also ran into this, pretty sure the bug is awalterschulze/gographviz#60

[ahhzaky]

How to use this?

[valdirmendesdev]

@Ruxton could you post your code as an example to reproduce the bug?