Replace Utils::JSON with corelib JSON calls.

Library/Homebrew/cmd/info.rb

Library/Homebrew/cmd/outdated.rb

Library/Homebrew/cmd/style.rb

Library/Homebrew/cmd/tap-info.rb

Library/Homebrew/descriptions.rb

Library/Homebrew/dev-cmd/boneyard-formula-pr.rb

Library/Homebrew/dev-cmd/bottle.rb

Library/Homebrew/dev-cmd/pull.rb

Library/Homebrew/download_strategy.rb

Library/Homebrew/tab.rb

Library/Homebrew/tap.rb

Library/Homebrew/test/json_test.rb

...brew/test/support/helper/integration_command_test_case.rb

Library/Homebrew/test/tab_test.rb

Library/Homebrew/utils/github.rb