update string-contains.js to use String.prototype.includes
update string-contains.js to use String.prototype.includes

toshok/echojs,carlosalberto/echo-js,toshok/echojs,carlosalberto/echo-js,toshok/echojs,toshok/echojs,toshok/echojs,carlosalberto/echo-js,toshok/echojs,toshok/echojs,carlosalberto/echo-js,carlosalberto/echo-js,carlosalberto/echo-js,toshok/echojs