Add bash to docker image

.gitlab-ci.yml

@@ -3,7 +3,7 @@ services:
   - docker:dind
 
 before_script:
-  - apk add git
+  - apk add git bash
   - git clone https://baltig.infn.it/mw-devel/helper-scripts.git helper-scripts
   - cp helper-scripts/scripts/* /usr/local/bin
   - docker login -u gitlab-ci-token -p ${CI_JOB_TOKEN} ${CI_REGISTRY}
@@ -30,4 +30,3 @@ push-to-dockerhub:
     - sh push-images.sh
   only:
       - master
-