Fix jquery won't run unless you refresh page

Turblinks, which drastically improves performance when using jquery, has
a couple of issues with document loading and can break functions that
rely on page loading. The jquery-turbolinks gen fixes this.

1- Install jquery-turbolinks gem:
gem jquery-turbolinks

2 - In application.js, require it immediately after requiring jquery:

//= require jquery
//= require jquery.turbolinks

3 - Restart server