Move gitlab secrets to file in .gitignore and replace with example file

.gitignore

+group_vars/dev_environments.yml

group_vars/dev_environments.yml → group_vars/dev_environments.yml.example

 docker:
   registry_url: gitlab.geant.net:5005/docker/ci_registry
-  username: # first.lastname
-  private_token: # some-secret-token
+  username: first.lastname
+  private_token: my-secret-token
 
 nat_user: nat

roles/containerlab/tasks/main.yml

@@ -16,6 +16,7 @@
     registry_url: '{{ docker.registry_url }}'
     username: '{{ docker.username }}'
     password: '{{ docker.private_token }}'
+  no_log: true
 
 - name: Pull vMX image from Docker repository
   community.docker.docker_image: