Python 在 20201010 之后的 pip3 install
在 2020 年 10 月 10 日之后 pip3 install 会发生错误：
ERROR: After October 2020 you may experience errors when installing or updating packages. This is because pip will change the way that it resolves dependency conflicts. We recommend you use --use-feature=2020-resolver to test your packages with the new resolver before it becomes the default. astroid 2.4.2 requires lazy-object-proxy==1.4.*, but you'll have lazy-object-proxy 1.5.1 which is incompatible.
$ pip3 install xxx --use-feature=2020-resolver