like `pyenv versions`, show "*" on the start of line if the environment is enabled
like `pyenv versions`, show "*" on the start of line if the environment
is enabled

pyenv/pyenv-virtualenv,cehoffman/pyenv,yyuu/pyenv-virtualenv,jerr0328/pyenv-virtualenv,aristiden7o/pyenv-virtualenv,cehoffman/pyenv,yeonsh/pyenv-virtualenv