MiniQhull generating more vertices than there are points in sample.

In the following code
```
using MiniQhull

function f(u)
x,y,z = u
M1, M2, B = [0.0, 0.795, 0.7]
xn = y
yn = z
zn = M1 + B*x + M2*y - z^2
return (xn, yn, zn)
end

u = (0.5,0.5,0.0)
sample = [u]
for i in 1:4000
global u = f(u)
end

for i in 1:750
global u = f(u)
push!(sample, u)
end
sample = sample[2:end]

d = delaunay(sample, "qhull d Qt Qbb Qc Qz Pp QJ")
````
sample has 750 points but d has points labeled 1 through 751.