Fix commented-out example

[matbesancon]

In http://juliastats.github.io/GLM.jl/stable/#Minimal-examples-1 The commented out part is not commented out, we should remove it or make it work, it looks odd on the doc page cc @andreasnoack

[andreasnoack]

I hadn't realized that it showed up like that in the docs. It should indeed be fixed somehow.