Add more type signatures.

Library/.rubocop.yml

Library/Homebrew/bintray.rb

Library/Homebrew/cask/artifact/abstract_artifact.rb

Library/Homebrew/cask/artifact/abstract_uninstall.rb

Library/Homebrew/cask/artifact/artifact.rb

Library/Homebrew/cask/artifact/mdimporter.rb

Library/Homebrew/cask/artifact/moved.rb

Library/Homebrew/cask/artifact/prefpane.rb

Library/Homebrew/cask/artifact/qlplugin.rb

Library/Homebrew/cask/artifact/relocated.rb

Library/Homebrew/cask/artifact/stage_only.rb

Library/Homebrew/cask/artifact/suite.rb

Library/Homebrew/cask/artifact/symlinked.rb

Library/Homebrew/cask/audit.rb

Library/Homebrew/cask/cask.rb

Library/Homebrew/cask/cask_loader.rb

Library/Homebrew/cask/cmd.rb

Library/Homebrew/cask/cmd/--cache.rb

Library/Homebrew/cask/cmd/abstract_command.rb

Library/Homebrew/cask/cmd/abstract_internal_command.rb