Add test for upgrading from previous version of oss to current

test/integration/oss-upgrade.yml

@@ -0,0 +1,21 @@
+---
+- name: Standard test for single node setup. Tests idempotence.
+  hosts: localhost
+  tasks:
+    - include: elasticsearch/test/integration/debug.yml
+  roles:
+    - { role: elasticsearch, es_instance_name: "node1" }
+  vars:
+    es_version: "{{ '6.2.4' if es_major_version == '6.x' else '5.6.9' }}" # This is set to an older version than the current default to force an upgrade
+    es_enable_xpack: false
+    es_heap_size: "1g"
+
+- name: Standard test for single node setup. Tests idempotence.
+  hosts: localhost
+  tasks:
+    - include: elasticsearch/test/integration/debug.yml
+  roles:
+    - { role: elasticsearch, es_instance_name: "node1" }
+  vars:
+    es_enable_xpack: false
+    es_heap_size: "1g"