add a helpful link to setup.py
add a helpful link to setup.py

ultimate-pa/benchexec,sosy-lab/benchexec,sosy-lab/benchexec,IljaZakharov/benchexec,cheshire/benchexec,sosy-lab/benchexec,IljaZakharov/benchexec,ultimate-pa/benchexec,bjowac/impara-benchexec,martin-neuhaeusser/benchexec,michkot/benchexec,IljaZakharov/benchexec,sosy-lab/benchexec,martin-neuhaeusser/benchexec,IljaZakharov/benchexec,cheshire/benchexec,martin-neuhaeusser/benchexec,sosy-lab/benchexec,dbeyer/benchexec,ultimate-pa/benchexec,dbeyer/benchexec,ultimate-pa/benchexec,dbeyer/benchexec,cheshire/benchexec,ultimate-pa/benchexec,dbeyer/benchexec,bjowac/impara-benchexec,ultimate-pa/benchexec,martin-neuhaeusser/benchexec,sosy-lab/benchexec,michkot/benchexec,michkot/benchexec,bjowac/impara-benchexec