swiftlint升级

~/Opal/iOS/App (mike/lyrics) $ which brew
/usr/local/bin/brew
~/Opal/iOS/App (mike/lyrics) $ cd /usr/local/bin/
/usr/local/bin (master) $ git pull origin master
From *https://github.com/Homebrew/brew*
* branch            master     -> FETCH_HEAD
Already up-to-date.
/usr/local/bin (master) $ brew update