Update static inventory example

The example static inventory did not contain the required child
groups so was not a valid inventory file.

Change-Id: If082340fad330f70786ff9a7e847caee9a88a3ca

inventory/inventory.ini

@@ -140,6 +140,10 @@ manila_api
 manila_scheduler
 manila_data
 manila_share
+[manila_api]
+[manila_scheduler]
+[manila_data]
+[manila_share]
 
 [masakari_all:children]
 masakari_api
@@ -154,6 +158,11 @@ mistral_api
 mistral_engine
 mistral_executor
 mistral_notifier
+[mistral_api]
+[mistral_engine]
+[mistral_executor]
+[mistral_notifier]
+
 
 [neutron_all:children]
 neutron_agent
@@ -203,9 +212,11 @@ nova_scheduler
 
 [panko_all:children]
 panko_api
+[panko_api]
 
 [placement_all:children]
 placement_api
+[placement_api]
 
 [rsyslog_all]