[CE-451] Make deployment of HL Composer optional

Adds a conditional switch to the ansible task to deploy
composer, which defaults to 'true' so that original
behavior is preserved when no setting is provided.

Change-Id: I0be370b8323cf608d656595a5ef6ba216b43ea96
Signed-off-by: Alex Meijer <alex@corsha.com>

src/agent/ansible/roles/deploy_compose/plays.yml

@@ -54,4 +54,5 @@
     - "./../../vars/{{ env }}.yml"
   tasks:
     - include_tasks: "composersetup/tasks/{{ mode }}.yml"
+      when: fabric.composer == true or fabric.composer is undefined
   tags: "composersetup"