Ignore session files

Symfony.gitignore

@@ -7,11 +7,13 @@
 # Email spool folder
 /app/spool/*
 
-# Cache and logs (Symfony3)
+# Cache, session files and logs (Symfony3)
 /var/cache/*
 /var/logs/*
+/var/sessions/*
 !var/cache/.gitkeep
 !var/logs/.gitkeep
+!var/sessions/.gitkeep
 
 # Parameters
 /app/config/parameters.yml