Update .travis.yml

Author: bwagner5

.travis.yml

@@ -45,7 +45,7 @@ jobs:
       name: Helm Sync and Version Test
     - stage: Deploy
       if: type = push AND env(DOCKER_USERNAME) IS present
-      script: sync-readme-to-dockerhub
+      script: make sync-readme-to-dockerhub
       name: Sync Readme to Dockerhub
     - stage: Deploy
       if: type = push AND tag =~ /^v\d+\.\d+(\.\d+)?(-\S*)?$/ AND env(DOCKER_USERNAME) IS present