.travis.yml in search_flip-2.3.1 vs .travis.yml in search_flip-2.3.2

@@ -5,12 +5,13 @@
   - ES_IMAGE=elasticsearch:1
   - ES_IMAGE=plainpicture/elasticsearch:2.4.1_delete-by-query
   - ES_IMAGE=elasticsearch:5.4
   - ES_IMAGE=docker.elastic.co/elasticsearch/elasticsearch:6.7.0
   - ES_IMAGE=docker.elastic.co/elasticsearch/elasticsearch:7.0.0
-  - ES_IMAGE=docker.elastic.co/elasticsearch/elasticsearch:7.3.0
+  - ES_IMAGE=docker.elastic.co/elasticsearch/elasticsearch:7.4.0
 rvm:
   - ruby-2.6.2
+  - ruby-2.7.1
 before_install:
   - docker-compose up -d
   - sleep 10
 install:
   - travis_retry bundle install