Add Inception bottlenecks and their pre-Relu versions to the graph.

def _populate_inception_bottlenecks(scope):
  """Add Inception bottlenecks and their pre-Relu versions to the graph."""
  graph = tf.get_default_graph()
  for op in graph.get_operations():
    if op.name.startswith(scope+'/') and 'Concat' in op.type:
      name = op.name.split('/')[1]
      pre_relus = []
      for tower in op.inputs[1:]:
        if tower.op.type == 'Relu':
          tower = tower.op.inputs[0]
        pre_relus.append(tower)
      concat_name = scope + '/' + name + '_pre_relu'
      _ = tf.concat(pre_relus, -1, name=concat_name)