Added v1.6 to the build

Signed-off-by: Jatin Naik <jnaik@pivotal.io>

.travis.yml

diff --git a/.travis.yml b/.travis.yml
index d65d227..6992f2a 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,6 +1,7 @@
 language: go
 go:
   - 1.5
+  - 1.6
   - stable
 
 install: