tensorflow隐藏编译警告SSE4.2 and AVX instructions

在使用tensorflow遇到SSE4.2 and AVX instructions编译警告时，可以添加下面代码隐藏警告
To hide those warnings, you could do this before your actual code.

import os
os.environ['TF_CPP_MIN_LOG_LEVEL']='2'
import tensorflow as tf

详见https://stackoverflow.com/questions/41293077/how-to-compile-tensorflow-with-sse4-2-and-avx-instructions