Merge pull request elastic#647 from fxdgear/nick/fix_test_children_are_reindex_correctly

Use version 6.0.0

Author: fxdgear

.travis.yml

@@ -24,7 +24,7 @@ before_install:
   - java -version
 
 install:
-  - curl -L -o /tmp/es-snap.zip https://artifacts.elastic.co/downloads/elasticsearch/elasticsearch-5.4.1.zip
+  - curl -L -o /tmp/es-snap.zip https://artifacts.elastic.co/downloads/elasticsearch/elasticsearch-6.0.0-beta2.zip
   - unzip /tmp/es-snap.zip -d /tmp/
   - /tmp/elasticsearch-*/bin/elasticsearch -E script.inline=true -E path.repo=/tmp -E repositories.url.allowed_urls='http://*' -E node.attr.testattr=test -d
   - git clone https://github.com/elastic/elasticsearch.git ../elasticsearch