Make names in promote job unique

Update task names so that it's clear which task is doing what and thus
we avoid e.g twice "Set target directory" and you need to check whether that
is correct.

Add missing task name for one include_role.

Change-Id: I550307bdfdf2815ce7b5001bd89928311ce8cc02

playbooks/docs/promote.yaml

@@ -20,16 +20,17 @@
       unarchive:
         src: "{{ zuul.executor.work_root }}/docs-html.tar.bz2"
         dest: "{{ zuul.executor.work_root }}/docs"
-    - include_role:
+    - name: Write root_marker file
+      include_role:
         name: write-root-marker
       when: "write_root_marker"
       vars:
         root_marker_dir: "{{ zuul.executor.work_root }}/docs"
-    - name: Set target directory
+    - name: Set target directory if master
       when: "zuul.branch == 'master'"
       set_fact:
         target_dir: "{{ afs.docs_master_path }}"
-    - name: Set target directory
+    - name: Set target directory if not master
       when: "zuul.branch != 'master'"
       set_fact:
         target_dir: "{{ afs.docs_branch_path }}"

roles/write-root-marker/tasks/main.yaml

@@ -1,9 +1,9 @@
-- name: Write root marker
+- name: Write root marker if zuul.branch
   when: "zuul.branch is defined"
   copy:
     dest: "{{ root_marker_dir }}/.root-marker"
     content: "Project: {{ zuul.project.name }} Branch: {{ zuul.branch }} Build: {{ zuul.build }} Revision: {{ zuul.ref }}"
-- name: Write root marker
+- name: Write root marker if zuul.tag
   when: "zuul.tag is defined"
   copy:
     dest: "{{ root_marker_dir }}/.root-marker"