New version fixes known bug in GraphicalModels.m2

In the current version of GraphicalModels, the following code would create an error

restart
 loadPackage "GraphicalModels"
 f = () -> (
    R := gaussianRing G;
    gaussianVanishingIdeal R)
    G = graph({{a,b},{b,c},{c,d},{a,d}})
 f()

In this version of GraphicalModels, Mike Stillman and Luis Garcia rewrote part of the code in gaussianRing, a few other methods to remove this bug. I am not sure if the certification must be commented out. I did commented out the certification in my local copy and the package was able to install, it passed all the tests and the bug has been squashed.