[7.x] add support for elasticsearch 7.x and remove support for 5.x (#558)

- add support for elasticsearch 7.x
- remove support for elasticsearch 5.x
- update kitchen-ansible configuration (install ansible and jmespath dependencies using os repositories)
- replace geoip plugin in tests as this one is now embeded in elasticsearch since 6.7.0 (cf. https://www.elastic.co/guide/en/elasticsearch/plugins/6.7/ingest-geoip.html)
- update discovery configuration for 7.x (in ES 7.x, discovery.zen.ping.unicast.hosts is replaced by discovery.seed_hosts and transport.tcp.port is replaced by transport.port, also discovery.seed_hosts is disabled on master nodes to avoid "master_not_discovered_exception" error when creating templates in the same play)
- update index template structure for 7.x 
- update security realms settings for 7.x (cf. https://www.elastic.co/guide/en/elasticsearch/reference/current/breaking-changes-7.0.html#include-realm-type-in-setting)

test/integration/multi.yml

@@ -10,20 +10,27 @@
     es_instance_name: "master"
     es_data_dirs:
       - "/opt/elasticsearch/master"
-    es_config:
+    es_config_6x:
       discovery.zen.ping.unicast.hosts: "localhost:9300"
       http.port: 9200
       transport.tcp.port: 9300
       node.data: false
       node.master: true
       bootstrap.memory_lock: true
+    es_config_7x:
+      http.port: 9200
+      transport.port: 9300
+      node.data: false
+      node.master: true
+      bootstrap.memory_lock: true
+    es_config: "{{ es_config_7x if es_major_version == '7.x' else es_config_6x }}"
     es_enable_xpack: false
     es_scripts: true
     es_templates: true
     es_heap_size: "1g"
     es_api_port: 9200
     es_plugins:
-      - plugin: ingest-geoip
+      - plugin: ingest-attachment
 
 - name: Elasticsearch Multi test - data on 9201
   hosts: localhost
@@ -38,14 +45,21 @@
     es_heap_size: "1g"
     es_api_port: 9201
     es_plugins:
-      - plugin: ingest-geoip
+      - plugin: ingest-attachment
     es_instance_name: "node1"
-    es_data_dirs: 
+    es_data_dirs:
       - "/opt/elasticsearch/data-1"
       - "/opt/elasticsearch/data-2"
-    es_config: 
+    es_config_6x:
       discovery.zen.ping.unicast.hosts: "localhost:9300"
       http.port: 9201
       transport.tcp.port: 9301
       node.data: true
       node.master: false
+    es_config_7x:
+      discovery.seed_hosts: "localhost:9300"
+      http.port: 9201
+      transport.port: 9301
+      node.data: true
+      node.master: false
+    es_config: "{{ es_config_7x if es_major_version == '7.x' else es_config_6x }}"