Fix Python 3 Syntax Errors (en masse)

research/neural_gpu/neural_gpu_trainer.py

@@ -14,6 +14,8 @@
 # ==============================================================================
 """Neural GPU."""
 
+from __future__ import print_function
+
 import math
 import os
 import random

research/neural_programmer/neural_programmer.py

@@ -18,6 +18,8 @@ This file calls functions to load & pre-process data, construct the TF graph
 and performs training or evaluation as specified by the flag evaluator_job
 Author: aneelakantan (Arvind Neelakantan)
 """
+from __future__ import print_function
+
 import time
 from random import Random
 import numpy as np