pip install :THESE PACKAGES DO NOT MATCH THE HASHES FROM THE REQUIREMENTS FILE

在docker 容器里通过代理 执行pip install 时，经常出现如下报错：

# pip install --proxy https://ip:port grpcio
Collecting grpcio
  Downloading grpcio-1.4.0-cp27-cp27mu-manylinux1_x86_64.whl (5.4MB)
    76% |########################        | 4.1MB 13kB/s eta 0:01:39
THESE PACKAGES DO NOT MATCH THE HASHES FROM THE REQUIREMENTS FILE. If you have updated the package versions, please update the hashes. Otherwise, examine the package contents carefully; someone may have tampered with them.
    grpcio from https://pypi.python.org/packages/b5/a8/a60298b70fbba8704f2c4a308baafdb6246bdb8b24c4d6f2de7d1ba23fec/grpcio-1.4.0-cp27-cp27mu-manylinux1_x86_64.whl#md5=deb2634935ce5b05e21e60615b9d7258:
        Expected md5 deb2634935ce5b05e21e60615b9d7258
             Got        d541e27a9ec7fa5003d38918e7e28167

这是由于网速太慢了，没有下载完整的文件，所以不完整的文件的md5和期望的不一样。

其实解决方法就是多试几次，说不定那一次网络环境好一点，就下载成功了呢。