2 small bug fixes - Invalid JSON and an invalid URL

Hey

Thanks for making L4withSentry I am finding it really useful! I have found two issues while using it:

First issue - When using composer install there is an extra comma causing the JSON to be invalid.

Second - After installing it and logging in. The link to view your account profile in the Bootstrap nav bar does not work if you're project is in a subfolder.  I have switched it to use Laravel's URL::to method so that it works in all cases!