Add go fmt to build

.travis.yml

@@ -16,6 +16,7 @@ before_install:
 
 script:
 - go test -v -race ./...
+- if [[ -n $(go fmt ./...) ]]; then echo "Please run go fmt on your code." && exit 1; fi
 
 notifications:
   flowdock: 15e08f7ed3a8fd2d89ddb36435301c1a