Upgrade to Laravel 5.2
Summary: Reference: https://laravel.com/docs/5.2/upgrade#upgrade-5.2.0
Test Plan:
- phpunit --no-coverage
- php artisan config:show
- php artisan phabricator:projectsmap
- Send a payload
Reviewers: dereckson
Differential Revision: http://devcentral.nasqueron.org/D198