Install vagrant
$ brew cask install vagrant
==> Downloading https://releases.hashicorp.com/vagrant/1.8.7/vagrant_1.8.7.dmg
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==> Verifying checksum for Cask vagrant
==> Running installer for vagrant; your password may be necessary.
==> Package installers may write to any location; options such as --appdir are ignored.
Password:
==> installer: Package name is Vagrant