Make the Homebrew/cask and Homebrew/homebrew-core style more closely
match the rest of Homebrew.
To accomplish this:
- Run `brew cask style` to ensure we don't break style there when
making changes or upgrading RuboCop in Homebrew/brew.
- Fix the HomepageMatchesUrl cop to better handle weird input.
- Remove the now unneeded `.rubocop_shared.yml`
- Fix the cask fixtures with `brew cask style --fix`.
- Share more style between Homebrew/brew, casks and formulae.
'cask upgrade' command collects all exceptions thrown
from individual casks during the upgrade process. If
there were more than one cask that raised exceptions
during the upgrade process, a MultipleCaskErrors
exception will be thrown.
Issue #5203
