Upgraded to Laravel 5.5 LTS

Knowfox now runs on the latest version of the Laravel framework, Laravel 5.5 LTS.

This is a version with long time support. There have been lots and lots of goodies and fixes added to Laravel for this version.

With this upgrade, I have also included a possible fix for the timeout that occurs when a form is kept open for a long time. This fix follows a discussion on Laracasts. Let's see if this fixes the issue.