Fix Travis-CI build error.

* error because merge of #711. The old issue don't check pre-commit
  hooks.

python/paddle/trainer/PyDataProvider2.py

@@ -202,6 +202,7 @@ class CheckWrapper(object):
         for each in item:
             callback(each)
 
+
 class CheckInputTypeWrapper(object):
     def __init__(self, generator, input_types, logger):
         self.generator = generator
@@ -221,6 +222,7 @@ class CheckInputTypeWrapper(object):
                     (repr(type(items)), repr(type(self.input_types))))
                 raise
 
+
 def provider(input_types=None,
              should_shuffle=None,
              pool_size=-1,
@@ -374,8 +376,8 @@ def provider(input_types=None,
                     self.generator = InputOrderWrapper(self.generator,
                                                        self.input_order)
                 else:
-                    self.generator = CheckInputTypeWrapper(self.generator, self.slots,
-                                                           self.logger) 
+                    self.generator = CheckInputTypeWrapper(
+                        self.generator, self.slots, self.logger)
                 if self.check:
                     self.generator = CheckWrapper(self.generator, self.slots,
                                                   check_fail_continue,