chore(ci): enable secret detection

- https://docs.gitlab.com/ee/user/application_security/secret_detection/
- Closes !8

.gitlab-ci.yml

@@ -1,12 +1,12 @@
 stages:
-  - build
+  - test
   - deploy
   - failed_stage
 
 image: alpine:latest # Use the latest version of Alpine Linux docker image
 
 build_job:
-  stage: build
+  stage: test
 
   before_script:
     - 'which ssh-agent || (apk update && apk add curl openssh-client git grep)'
@@ -78,3 +78,6 @@ failed_job:
     - if: '$CI_COMMIT_REF_NAME == "master" && ($CI_PIPELINE_SOURCE == "schedule" || $CI_PIPELINE_SOURCE == "web")'
       # Run this job only when preceding jobs failed
       when: on_failure
+
+include:
+  - template: Security/Secret-Detection.gitlab-ci.yml