Add gofmt Stage in Travis.yml

Author: asifdxtreme

.travis.yml

@@ -6,6 +6,8 @@ install:
 - mv $TRAVIS_BUILD_DIR $HOME/gopath/src/k8s.io/kube-state-metrics
 jobs:
   include:
+    - stage: Go fmt
+      script: make gofmtcheck
     - stage: Unit Test
       script: make test-unit
     - stage: Build