ubuntu 18.04 install tensorflow-nightly-gpu and tfp-nightly

因学习tensorflow probability，需要安装tensorflow nightly gpu和tfp-nightly，安装步骤如下：
1、不能在anconda环境下，本身也不支持nightly版本，且遇到一些奇怪的权限问题。
2、参照How to Create Python Virtual Environments on Ubuntu 18.04安装虚拟环境。(python3 -m venv my-project-env)
3、更新pip，pip3 install --upgrade pip
4、更新setuptools, pip install --upgrade setuptools.
If you do not update setuptools, you may encounter the similar following error when install tf-nightly-gpu.
ERROR: google-auth 1.11.0 has requirement setuptools>=40.3.0, but you’ll have setuptools 39.0.1 which is incompatible.
ERROR: tb-nightly 2.2.0a20200106 has requirement setuptools>=41.0.0, but you’ll have setuptools 39.0.1 which is incompatible.
5、pip install tf-nightly-gpu
6、pip install tfp-nightly