Update .gitlab-ci.yml

.gitlab-ci.yml

 sonar_preview:
   stage: test
   script:
-    - ci/sonar_preview.sh
+    - bash ci/sonar_preview.sh
   except:
     - master
   tags:
@@ -9,7 +9,7 @@ sonar_preview:
 
 auto_test:
   stage: test
-  script: ci/auto_test.sh
+  script: bash ci/auto_test.sh
   except:
     - master
   tags:
@@ -18,7 +18,7 @@ auto_test:
 sonar_analyze:
   stage: test
   script:
-    - ci/sonar_analyze.sh
+    - bash ci/sonar_analyze.sh
   only:
     - master
   tags: