message: Update head.py
  * Update head.py
  Use tf.losses instead of deprecated contrib
  * Update head.py
  Corrected incorrect import statement
  * Update head.py
  Correcting shape
  * Update head.py
  Entered correct type for reduction
  * Update head.py
  Improve naming convention
diff: @@ -25,8 +25,7 @@ import six
  from tensorflow.contrib import framework as framework_lib
  from tensorflow.contrib import layers as layers_lib
  from tensorflow.contrib import lookup as lookup_lib
  -# TODO(ptucker): Use tf.losses and tf.metrics.
  -from tensorflow.contrib import losses as losses_lib
  +# TODO(ptucker): Use tf.metrics.
  from tensorflow.contrib import metrics as metrics_lib
  from tensorflow.contrib.learn.python.learn.estimators import constants
  from tensorflow.contrib.learn.python.learn.estimators import model_fn
  @@ -44,6 +43,7 @@ from tensorflow.python.ops import sparse_ops
  from tensorflow.python.ops import string_ops
  from tensorflow.python.ops import variable_scope
  from tensorflow.python.ops import weights_broadcast_ops
  +from tensorflow.python.ops.losses import losses as losses_lib
  from tensorflow.python.platform import tf_logging as logging
  from tensorflow.python.summary import summary
  from tensorflow.python.training import training
  @@ -1212,7 +1212,8 @@ class _BinarySvmHead(_SingleHead):
  with ops.name_scope(None, "hinge_loss", (logits, labels)) as name:
  with ops.control_dependencies((_assert_labels_rank(labels),)):
  labels = array_ops.reshape(labels, shape=(-1, 1))
  - loss = losses_lib.hinge_loss(logits=logits, labels=labels, scope=name)
  + loss = losses_lib.hinge_loss(labels=labels, logits=logits, scope=name,
  + reduction=losses_lib.Reduction.NONE)
  return _compute_weighted_loss(loss, weights)
  super(_BinarySvmHead, self).__init__(
  