length in NewRect(p Point, lengths []float64) may be zero

[warrenwyf]

Consider a point or a line which has the same y coordinates, the length of bounding box may be zero

[Sven Sauleau]

We ended up adding an epsilon (something like 0,0001) if the box had a 0 lentgh.

I can make a PR if you're fine with this solution.

[Daniel Connelly]

Sure, I'll happily accept a PR!