Update travis config

.travis.yml

diff --git a/.travis.yml b/.travis.yml
index 580ad22..0a7c136 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -5,8 +5,12 @@
 go:
         - 1.5.4
         - 1.6.3
+        - 1.7
         - tip
 
+matrix:
+        allow_failures:
+                  - go: tip
 install:
         - go get github.com/golang/lint/golint
         - export PATH=$GOPATH/bin:$PATH