pyyaml 설치 시 인코딩 error 문제 해결방법

Add a solution here:

run a new cmd.exe console
chcp
it will show the system default code, for example 936.
open Lib/site-package/pip/compat/__init__.py
around 75 line, change return s.decode('utf_8') to return s.decode('cp936')

It's just a workaround. I think pip might need solve this issue asap, it's not easy to find solution.

This may have a general solution using cdll.
Not sure if this is the best solution on windows but I still made a PR for this issue.

< 참고 : https://github.com/pypa/pip/issues/4251 >