CI: utilise bash comme shell.

Au lieu d'ash.

.gitlab-ci.yml

@@ -9,9 +9,9 @@ build:
   variables:
     NPM_CONFIG_CACHE: "$CI_PROJECT_DIR/.npm"
   before_script:
-    - apk update && apk add make
+    - apk update && apk add make bash
   script:
-    - make
+    - env SHELL=/bin/bash make
   artifacts:
     name: dist
     expire_in: 2 years