.travis update adding 1.7 and allowing tip fail

Author: mcuadros

.travis.yml

@@ -3,8 +3,13 @@ go:
  - 1.4
  - 1.5
  - 1.6
+ - 1.7
  - tip
 
+matrix:
+  allow_failures:
+    - go: tip
+
 install:
  - rm -rf $GOPATH/src/gopkg.in/mcuadros
  - mkdir -p $GOPATH/src/gopkg.in/mcuadros