create a meta file to execute sub roles. Remove / add blank lines at the end. Add mock

main.yml

@@ -0,0 +1,10 @@
+---
+- name: Deploy and configure a runner on target machine
+  hosts: gitrunner
+  become: true
+  gather_facts: true
+
+  roles:
+    - update.yml
+    - host_setup.yml
+    - runner_setup.yml