安装扩展源：sudo yum -y install epel-release
安装python-pip模块：sudo yum install python-pip
直接把whl文件download下来安装，cpu版本的tensorflow地址为：https://pypi.org/project/tensorflow/1.7.0/#files，打开之后可以看
到tensorflow-1.7.0-cp27-cp27mu-manylinux1_x86_64.whl下载链接
pip install tensorflow-1.7.0-cp27-cp27mu-manylinux1_x86_64.whl
测试安装是否成功：
执行python：
>>>import tensorflow as tf
>>>tf.__version__
>>>tf.__path__