sampling

Is your feature request related to a problem? Please describe.
Even after the useful PR GeomScale/volesti#190 some examples are still failing to compile.

Describe the solution you'd like
Some have an easy fix e.g. vpolytope-volume while some other e.g. EnvelopeProblemSOS need some work to fix the cmake (at least in my Ubuntu 20.04 with gcc version `9.3