update boltzmann_action definition

To solve the 
ValueError: sum(pvals[:-1]) > 1.0 
as described in endgameinc#7

test_agent_kerasrl.py

@@ -39,7 +39,7 @@ def evaluate( action_function ):
 
     # option 1: Boltzmann sampling from Q-function network output
     softmax = lambda x : np.exp( x ) / np.sum( np.exp( x ))
-    boltzmann_action = lambda x : np.argmax( np.random.multinomial( 1, softmax(x).flatten())) 
+    boltzmann_action = lambda x : np.random.choice( range(len(x)), p=softmax(x).flatten())
     # option 2: maximize the Q value, ignoring stochastic action space
     best_action = lambda x : np.argmax( x )
 
@@ -70,4 +70,4 @@ def f(bytez):
     print("Success rate of random chance: {}\n".format( len(random_success) / total ))
     print("Success rate (dqn): {}\n".format( len(dqn_success) / total ) )
     print("Success rate (dqn): {}\n".format( len(dqn_score_success) / total ) )          
-
+