Update .gitlab-ci.yml file

.gitlab-ci.yml

@@ -29,6 +29,8 @@ test-frontend:
 test-backend:
   image: python:3.8
   stage: test-backend
+  tags:
+    - docker
   script:
     - cd backend/secfit
     - apt-get update -qy
@@ -39,6 +41,8 @@ deploy:
   type: deploy
   image: ruby
   stage: deploy
+  tags:
+    - docker
   script:
     - apt-get update -qy
     - apt-get install -y ruby-dev