验证tensorflow-GPU，cuda，cudnn配置是否成功

import tensorflow as tf

tensorflow_version = tf.__version__
gpu_available = tf.test.is_gpu_available()

print('tensorflow version:',tensorflow_version, '\tGPU available:', gpu_available)

a = tf.constant([1.0, 2.0], name='a')
b = tf.constant([1.0, 2.0], name='b')
result = tf.add(a,b, name='add')
print(result)