Add day 20, Elasticsearch with Symfony2
Merge branch 'migrate_to_sf2_3' into 20-elasticsearch

Conflicts:
	src/Afsy/Bundle/FrontBundle/Controller/AventController.php
Typo on 20 author bio
Merge pull request #68 from damienalexandre/20-elasticsearch

Day 20 - Elasticsearch in your Symfony2 app