travis push lastest as hash commit tag (#323)

diff --git a/tools/travis/deploy.sh b/tools/travis/deploy.sh
index adc5c9d..2950a57 100755
--- a/tools/travis/deploy.sh
+++ b/tools/travis/deploy.sh
@@ -30,3 +30,9 @@
 
 echo docker push ${dockerhub_image}
 docker push ${dockerhub_image}
+# if doing latest also push a tag with the hash commit
+if [ ${dockerhub_image_tag} == "latest" ]; then
+SHORT_COMMIT=`git rev-parse --short HEAD`
+docker tag ${dockerhub_image} ${dockerhub_image_prefix}/${dockerhub_image_name}:${SHORT_COMMIT}
+docker push ${dockerhub_image_prefix}/${dockerhub_image_name}:${SHORT_COMMIT}
+fi