Add Redis to travis build

Author: abedra

.travis.yml

@@ -13,4 +13,7 @@ install:
   - go get github.com/gorilla/mux
   - go get github.com/gorilla/handlers
   - go get github.com/fzzy/radix/redis
-  - go get github.com/abh/geoip
+  - go get github.com/abh/geoip
+
+services:
+  - redis-server