Better management of inventory to pick up tags

Added a meta task to rebuild inventory. This causes the ec2.py script to
be run again and pick up the tags for the recently provisioned ec2
instances, so that the tags can be used as variables later in
plays/tasks.

ec2.ini

@@ -118,6 +118,7 @@ cache_path = ~/.ansible/tmp
 # seconds, a new API call will be made, and the cache file will be updated.
 # To disable the cache, set this value to 0
 #cache_max_age = 300
+cache_max_age = 0
 
 # Organize groups into a nested/hierarchy instead of a flat namespace.
 nested_groups = False

training_nodes.yml

@@ -236,8 +236,11 @@
         overwrite: yes
         wait: no
       loop: "{{ training_nodes.results }}"
+
+    - name: Refresh inventory to pick up ec2 tags
+      meta: refresh_inventory
 
-- hosts: ssh_training_node_hosts
+- hosts: tag_role_comanage_registry
   become: yes
   gather_facts: True
   strategy: free