Enabling-more-agents-for-Batch-RL-and-cleanup (#258)

allowing for the last training batch drawn to be smaller than batch_size + adding support for more agents in BatchRL by adding softmax with temperature to the corresponding heads + adding a CartPole_QR_DQN preset with a golden test + cleanups

rl_coach/agents/dfp_agent.py

@@ -146,13 +146,13 @@ class DFPAgent(Agent):
 
         network_inputs = batch.states(network_keys)
         network_inputs['goal'] = np.repeat(np.expand_dims(self.current_goal, 0),
-                                           self.ap.network_wrappers['main'].batch_size, axis=0)
+                                           batch.size, axis=0)
 
         # get the current outputs of the network
         targets = self.networks['main'].online_network.predict(network_inputs)
 
         # change the targets for the taken actions
-        for i in range(self.ap.network_wrappers['main'].batch_size):
+        for i in range(batch.size):
             targets[i, batch.actions()[i]] = batch[i].info['future_measurements'].flatten()
 
         result = self.networks['main'].train_and_sync_networks(network_inputs, targets)