Instant WordPress is currently using WordPress 4.1, but the most current WordPress version as of today is 4.3.1. Perhaps the easiest way to get the most recent version & updates for WordPress local development by using a stack with a WordPress installer.
I use AMPPS which runs on Windows, MacOS and Linux, and has a Softaculous installer for a bunch of scripts, including WordPress. I installed it last March for a few online classes (php, SQL, WordPress) and it worked flawlessly. I could look at my local files with WeBuilder and was able to install xdebug without any problems.
You can test your code using various php versions, and you can change versions on the fly.
http://www.ampps.com/tourYou can look at their 1-click install scripts here:
http://www.ampps.com/apps