changed optimizer to adam

neural_style.py

@@ -67,7 +67,7 @@ class TransferParams():
     num_iterations = 1000
     init = 'random'
     init_image = None
-    optimizer = 'lbfgs'
+    optimizer = 'adam'
     learning_rate = 1e0
     lbfgs_num_correction = 100
     print_iter = 50