chore(.travis.yml): use current Go 1.7 compiler

mboersma · mboersma · commit 4b147080adfe · 2016-08-19T11:42:36.000-06:00
diff --git a/.travis.yml b/.travis.yml
@@ -1,7 +1,7 @@
 sudo: required
 language: go
 go:
-  - 1.5.1
+  - 1.7
 branches:
   only:
     - master
