[meta] refactor kitchen tests (#765)

* [meta] refactor kitchen tests

This commit update kitchen tests to match important feature to test:
- default: test a deployment with all default values
- license: test a deployment with a license and default values
- trial: test a deployment with security enabled and trial license
- oss: test a deployment with oss version and default values (6.x only)
- upgrade: test an upgrade from a previous version
- oss-upgrade: test an upgrade with oss version (6.x only)
- oss-to-default-upgrade: test an upgrade from previous oss to latest
default version
- custom_config: test a deployment with custom config files
- security: test a deployment with security enabled

* [meta] fix license test

test/integration/oss-to-default-upgrade.yml

@@ -0,0 +1,19 @@
+---
+- name: Deploy Elasticsearch OSS version
+  hosts: localhost
+  post_tasks:
+    - include: elasticsearch/test/integration/debug.yml
+  roles:
+    - elasticsearch
+  vars:
+    es_version: "{{ '7.0.0' if es_major_version == '7.x' else '6.7.1' }}" # This is set to an older version than the current default to force an upgrade
+    oss_version: true
+
+- name: Upgrade to Elasticsearch default version
+  hosts: localhost
+  post_tasks:
+    - include: elasticsearch/test/integration/debug.yml
+  roles:
+    - elasticsearch
+  vars:
+    oss_version: false