Fix travis-ci in new image

Fix issue #2562

.travis.yml

-group: deprecated-2017Q2
 language: cpp
 cache:
   directories:

python/paddle/trainer_config_helpers/networks.py

@@ -1381,7 +1381,7 @@ def inputs(layers, *args):
     if len(args) != 0:
         layers.extend(args)
 
-    Inputs(*[l.name for l in layers])
+    Inputs(* [l.name for l in layers])
 
 
 def outputs(layers, *args):
@@ -1424,7 +1424,7 @@ def outputs(layers, *args):
     assert len(layers) > 0
 
     if HasInputsSet():  # input already set
-        Outputs(*[l.name for l in layers])
+        Outputs(* [l.name for l in layers])
         return  # just return outputs.
 
     if len(layers) != 1: