New features
[2022420] Updated the application to Symfony 2.8.4 (@bocharsky-bw)
[95a7464] Display in the template all kinds of flash messages (@bocharsky-bw)
[dc6db54] Made the retrieval of template source forward compatible with Twig 2.x (@stof)
Bug fixes
[73d2571] Reverted serializer name in config_prod.yml (@bocharsky-bw)
[3e0510f] Fixed SCSS compiling with Assetic (@f-plante)
[91010b6] Fix minor issues related to issues and Bootstrap template (@f-plante)
[851539a] Fixed the handling of flash messages (@f-plante)
[24006e1] Don't show a 404 error when visiting the first page of the blog and there are no posts (@f-plante)
[a5cb73f] Misc. fixes suggested by PhpStorm inspections (@javiereguiluz)