parse_boolean

# File lib/bundler/vendor/thor/lib/thor/parser/options.rb, line 183
    def parse_boolean(switch)
      if current_is_value?
        if ["true", "TRUE", "t", "T", true].include?(peek)
          shift
          true
        elsif ["false", "FALSE", "f", "F", false].include?(peek)
          shift
          false
        else
          !no_or_skip?(switch)
        end
      else
        @switches.key?(switch) || !no_or_skip?(switch)
      end
    end