Remove unused hostname var from test playbooks

Neither the rabbit, nor galera common tasks use
the hostname var that was defined, so we can remove
the var from all test playbooks.

Change-Id: I92c85c2c5c53f4e3d028debcfe925c26ad84284b

.gitignore

@@ -61,6 +61,8 @@ releasenotes/build
 
 # Test temp files
 tests/plugins
+tests/playbooks
+tests/test.retry
 
 # Vagrant testing artifacts
 .vagrant

test-install-glance.yml

@@ -22,11 +22,9 @@
       vhost_name: "{{ glance_rabbitmq_vhost }}"
       user_name: "{{ glance_rabbitmq_userid }}"
       user_password: "{{ glance_rabbitmq_password }}"
-      host_name: groups['glance_all'][0]
     - include: create-grant-db.yml
       db_name: "{{  glance_galera_database }}"
       db_password: "{{ glance_container_mysql_password }}"
-      host_name: groups['glance_all'][0]
   roles:
     - role: "{{ glance_rolename | default('os_glance') }}"
   vars_files:

test-install-keystone.yml

@@ -25,11 +25,9 @@
       vhost_name: "{{ keystone_rabbitmq_vhost }}"
       user_name: "{{ keystone_rabbitmq_userid }}"
       user_password: "{{ keystone_rabbitmq_password }}"
-      host_name: groups['keystone_all'][0]
     - include: create-grant-db.yml
       db_name: "{{ keystone_galera_database }}"
       db_password: "{{ keystone_container_mysql_password }}"
-      host_name: groups['keystone_all'][0]
   roles:
     - role: "{{ keystone_rolename | default('os_keystone') }}"
   vars_files:

test-install-neutron.yml

@@ -62,11 +62,9 @@
       vhost_name: "{{ neutron_rabbitmq_vhost }}"
       user_name: "{{ neutron_rabbitmq_userid }}"
       user_password: "{{ neutron_rabbitmq_password }}"
-      host_name: groups['neutron_all'][0]
     - include: create-grant-db.yml
       db_name: "{{ neutron_galera_database }}"
       db_password: "{{ neutron_container_mysql_password }}"
-      host_name: groups['neutron_all'][0]
   roles:
     - role: "{{ neutron_rolename | default('os_neutron') }}"
   vars_files:

test-install-nova.yml

@@ -38,15 +38,12 @@
       vhost_name: "{{ nova_rabbitmq_vhost }}"
       user_name: "{{ nova_rabbitmq_userid }}"
       user_password: "{{ nova_rabbitmq_password }}"
-      host_name: groups['nova_all'][0]
     - include: create-grant-db.yml
       db_name: "{{ nova_galera_database }}"
       db_password: "{{ nova_container_mysql_password }}"
-      host_name: groups['nova_all'][0]
     - include: create-grant-db.yml
       db_name: "{{ nova_api_galera_database }}"
       db_password: "{{ nova_container_mysql_password }}"
-      host_name: groups['nova_all'][0]
   roles:
     - role: "{{ nova_rolename | default('os_nova') }}"
   vars_files: