message: Update callbacks train/test batch end docs to mention that losses and metrics results are aggregated.
diff: @@ -390,7 +390,7 @@ class CallbackList(object):
  Arguments:
  batch: integer, index of batch within the current epoch.
  - logs: dict. Metric results for this batch.
  + logs: dict. Aggregated metric results up until this batch.
  """
  if self._should_call_train_batch_hooks:
  self._call_batch_hook(ModeKeys.TRAIN, 'end', batch, logs=logs)
  @@ -411,7 +411,7 @@ class CallbackList(object):
  Arguments:
  batch: integer, index of batch within the current epoch.
  - logs: dict. Metric results for this batch.
  + logs: dict. Aggregated metric results up until this batch.
  """
  if self._should_call_test_batch_hooks:
  self._call_batch_hook(ModeKeys.TEST, 'end', batch, logs=logs)
  @@ -432,7 +432,7 @@ class CallbackList(object):
  Arguments:
  batch: integer, index of batch within the current epoch.
  - logs: dict. Metric results for this batch.
  + logs: dict. Aggregated metric results up until this batch.
  """
  if self._should_call_predict_batch_hooks:
  self._call_batch_hook(ModeKeys.PREDICT, 'end', batch, logs=logs)
  @@ -648,7 +648,7 @@ class Callback(object):
  Arguments:
  batch: integer, index of batch within the current epoch.
  - logs: dict. Metric results for this batch.
  + logs: dict. Aggregated metric results up until this batch.
  """
  # For backwards compatibility.
  self.on_batch_end(batch, logs=logs)
  @@ -681,7 +681,7 @@ class Callback(object):
  Arguments:
  batch: integer, index of batch within the current epoch.
  - logs: dict. Metric results for this batch.
  + logs: dict. Aggregated metric results up until this batch.
  """
  @doc_controls.for_subclass_implementers
  @@ -706,7 +706,7 @@ class Callback(object):
  Arguments:
  batch: integer, index of batch within the current epoch.
  - logs: dict. Metric results for this batch.
  + logs: dict. Aggregated metric results up until this batch.
  """
  @doc_controls.for_subclass_implementers
  