since we are no longer using matrix types, then have to explicitly call dot...

since we are no longer using matrix types, then have to explicitly call dot function for dot product

mdp.py

@@ -1200,7 +1200,7 @@ class PolicyIteration(MDP):
             itr += 1
             
             Vprev = policy_V
-            policy_V = policy_R + self.discount * policy_P * Vprev
+            policy_V = policy_R + self.discount * policy_P.dot(Vprev)
             
             variation = absolute(policy_V - Vprev).max()
             if self.verbose: