adding test for CLHEP-155 bug report

Random/test/CMakeLists.txt

@@ -23,6 +23,7 @@ set( Random_simple_tests testSaveEngineStatus
                          testVectorSave
                          testBug58950 
                          testBug73093 
+                         testCLHEP155
                          testEngineCopy 
                          testDistCopy 
                          testZiggurat

Random/test/testCLHEP155.cc

+
+#include "CLHEP/Random/MixMaxRng.h"
+
+int main()
+try {
+  CLHEP::MixMaxRng eng(0); // Seeding with 0 is not supported; should throw.
+  return 1;
+}
+catch(...) {
+  return 0;
+}
+