Drop go tip from CI

It's never been useful and it fails a lot.

.travis.yml

@@ -20,7 +20,6 @@ before_install:
 - vagrant/boot_cluster.sh
 - vagrant/create_topics.sh
 
-
 install:
 - make install_dependencies
 
@@ -30,12 +29,4 @@ script:
 - make errcheck
 - make fmt
 
-matrix:
-  include:
-    - go: tip
-      env: KAFKA_VERSION=0.8.2.2
-  allow_failures:
-    - go: tip
-  fast_finish: true
-
 sudo: false