- moved "POST /card" to "POST /cards"
- changed status codes in possible responses
added `slug` to cards
- changed "GET /card/<id>" to "/cards/<slug>"
- removed filter from "GET /cards"
- changed "DELETE /card/<id>" to "DELETE /cards/<slug>"
- DELETE response are send 204 status code now
added URI in header of response after creating a new card
upgraded to codeception 1.8.0.1
updated/improved "PUT /cards/<slug>"
optimized using of \Symfony\Component\HttpFoundation\Response