Increased the number of MCMC rounds so that the bayes nets test

is less likely to indicate failure.

--HG--
extra : convert_revision : svn%3Afdd8eb12-d10e-0410-9acb-85c331704f74/trunk%403900

dlib/test/bayes_nets.cpp

@@ -335,7 +335,7 @@ namespace
         bayesian_network_gibbs_sampler sampler;
         matrix<double,1,8> counts;
         set_all_elements(counts, 0);
-        const unsigned long rounds = 100000;
+        const unsigned long rounds = 200000;
         for (unsigned long i = 0; i < rounds; ++i)
         {
             sampler.sample_graph(bn);