Add scrollRestoration option

lib/proto/parse-options.js

@@ -24,6 +24,7 @@ module.exports = function(options) {
   this.options.cacheBust = (typeof this.options.cacheBust === "undefined") ? true : this.options.cacheBust
   this.options.debug = this.options.debug || false
   this.options.timeout = this.options.timeout || 0
+  this.options.scrollRestoration = (typeof this.options.scrollRestoration !== "undefined") ? this.options.scrollRestoration : true
 
   // we can’t replace body.outerHTML or head.outerHTML
   // it create a bug where new body or new head are created in the dom