解決brew 更新慢的問題
cd "$(brew --repo)"
git remote set-url origin https://mirrors.tuna.tsinghua.edu.cn/git/homebrew/brew.git
git checkout master
git pull origin master
cd "$(brew --repo)/Library/Taps/homebrew/homebrew-core"
git remote set-url origin https://mirrors.tuna.tsinghua.edu.cn/git/homebrew/homebrew-core.git
git checkout master
git pull origin master
brew update