function isIdentifier(name, ecmaVersion) {
	if (ecmaVersion >= 2015) {
		return esutils.keyword.isIdentifierES6(name);
	}
	return esutils.keyword.isIdentifierES5(name);
}
Determines if a string name is a valid identifier
@param {string} name The string to be checked
@param {number} ecmaVersion The ECMAScript version if specified in the parserOptions config
@returns {boolean} True if the string is a valid identifier