def validate(command, allknifes)
      return if allknifes.index { |x| x.start_with?("knife #{command}") }

      STDERR.puts "ERROR: 'knife #{command}' is not a currently supported command for knife."
      exit(-1)
    end
def validate(command, allknifes)
      return if allknifes.index { |x| x.start_with?("knife #{command}") }

      STDERR.puts "ERROR: 'knife #{command}' is not a currently supported command for knife."
      exit(-1)
    end
test that the knife command exists