travis: add go1.7
diff --git a/.travis.yml b/.travis.yml
index 5f26f3f..82de377 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -4,6 +4,7 @@
   - 1.4
   - 1.5
   - 1.6
+  - 1.7
   - tip
 
 script: