lib/attributes.js
function isUnquoted(code) {
	return !isNaN(code) && !isQuote(code) && !isSpace(code) && !isTerminator(code);
}
function isUnquoted(code) {
	return !isNaN(code) && !isQuote(code) && !isSpace(code) && !isTerminator(code);
}
Check if given character code is valid unquoted value
@param  {Number}  code
@return {Boolean}