Add system python to pyenv

pyenv-relink.md

• link python folder to pyenv versions
• rehash pyenv shims

# link outside python folder to pyenv versions folder
ln -s /outside/python/x.x.x ~/.pyenv/versions/x.x.x

# Example add macos system python 2.7 to pyenv
ln -s /System/Library/Frameworks/Python.framework/Versions/2.7 ~/.pyenv/versions/2.7

# Finally (Required!!!)
pyenv rehash    # Rehash pyenv shims (run this after installing executables)