You are using pip version 10.0.1, however version 18.1 is available.问题解决

在GitHub中下载了Python源码，直接运行pip install -Ur requirements.txt，系统如下提示：
You are using pip version 10.0.1, however version 18.1 is available.
You should consider upgrading via the ‘python -m pip install --upgrade pip’ command.

直接运行 python -m pip install --upgrade pip