Better travis config. Enable APCu

Author: Nyholm

README.md

@@ -4,8 +4,8 @@
 This is a void implementation of PSR-6. Other names for this adapter could be Blackhole or Null. This 
 adapter does not save anything and will always return an empty CacheItem. 
 
-| Feature |   |
-| ------- | - | 
+| Feature | Supported |
+| ------- | --------- | 
 | Flush everything | No 
 | Expiration time | No
-| Support for tags | No
+| Tagging | Yes