mac 更新brew镜像源
cd "$(brew --repo)/Library/Taps/homebrew/homebrew-core"
git remote set-url origin git://mirrors.ustc.edu.cn/homebrew-core.git
echo 'export HOMEBREW_BOTTLE_DOMAIN=https://mirrors.ustc.edu.cn/homebrew-bottles' >> ~/.bash_profile
source ~/.bash_profile
brew update