message: add error message when importing contrib.tensorrt without libnvinfer
diff: @@ -19,7 +19,16 @@ from __future__ import division
  from __future__ import print_function
  # pylint: disable=unused-import,line-too-long
  +try:
  from tensorflow.contrib.tensorrt.python.ops import trt_engine_op
  from tensorflow.contrib.tensorrt.python.trt_convert import calib_graph_to_infer_graph
  from tensorflow.contrib.tensorrt.python.trt_convert import create_inference_graph
  +except:
  + no_trt_message = (
  + '**** Failed to initialize TensorRT. This is either because the TensorRT'
  + ' installation path is not in LD_LIBRARY_PATH, or because you do not have it'
  + ' installed. If not installed, please go to'
  + ' https://developer.nvidia.com/tensorrt to download and install'
  + ' TensorRT ****''')
  + print(no_trt_message)
  # pylint: enable=unused-import,line-too-long
  