Ignore logs for Symfony4

Source: https://symfony.com/doc/master/logging.html
Under Where Logs are Stored, added since Symfony 4.0

Symfony.gitignore

@@ -15,6 +15,10 @@
 !var/logs/.gitkeep
 !var/sessions/.gitkeep
 
+# Logs (Symfony4)
+/var/log/*
+!var/log/.gitkeep
+
 # Parameters
 /app/config/parameters.yml
 /app/config/parameters.ini