Only create certificate destination directories once.

If installing several certs or keys to a target the destination
directory creation task is run once for each list item even if
it is the same directory every time.

This patch filters the list of targets and reduces the list of
target directories to a unique list, reducing the number of loop
iterations required.

Change-Id: I7432463dfa067afed2f46874119378bfdf96639c

tasks/main_certs.yml

@@ -33,16 +33,16 @@
 
 - name: Create certificate destination directories
   file:
-    path: "{{ install.item.dest | dirname }}"
+    path: "{{ install }}"
     state: directory
     mode: "0755"
-  loop: "{{ _cert_slurp.results }}"
+  loop: "{{ _cert_slurp.results | map(attribute='item') | map(attribute='dest') | map('dirname') | unique }}"
   loop_control:
     loop_var: install
     label: "{{ loop_label | to_json }}"
   vars:
     loop_label:
-      path: "{{ install.item.dest | dirname }}"
+      path: "{{ install }}"
       state: directory
       mode: '0755'