ReplaceRoute bug

[lishine]

 replaceRoute = (name, params = {}, options) => {
    const { page, pattern } = this.getRoute(name)
    const { href, as } = createLinkProps(page, pattern, params)
    return Router.replace(href, as, options)
  }

  prefetchRoute = (name, params = {}) => {
    const { page, pattern } = this.getRoute(name)
    const { href } = createLinkProps(page, pattern, params)
    return Router.prefetch(href)
  }

Should be NextRouter

[lydell]

PR: #14