Add 1.5 and 1.6 test.

Signed-off-by: Bo-Yi Wu <appleboy.tw@gmail.com>

.travis.yml

@@ -2,7 +2,8 @@ language: go
 sudo: false
 go:
   - 1.4
-  - 1.4.2
+  - 1.5
+  - 1.6
   - tip
 
 script: