only push new docker images during CI if it's run against the master …

…branch

scripts/linux/push_docker.sh

@@ -5,5 +5,7 @@ DOCKER_USER=$2
 DOCKER_PASS=$3
 BRANCH_NAME=$4
 
-docker login -u $DOCKER_USER -p $DOCKER_PASS
-docker push aostreetart/aeselprojects:latest
+if [ "$BRANCH_NAME" == "master" ]; then
+  docker login -u $DOCKER_USER -p $DOCKER_PASS
+  docker push aostreetart/aeselprojects:latest
+fi