dip.yml in string_tools-0.16.0 vs dip.yml in string_tools-1.0.0

@@ -1,9 +1,9 @@
 version: '1'
 
 environment:
-  DOCKER_RUBY_VERSION: 2.3
-  RUBY_IMAGE_TAG: 2.3-latest
+  DOCKER_RUBY_VERSION: 2.4
+  RUBY_IMAGE_TAG: 2.4-latest
   COMPOSE_FILE_EXT: development
   RAILS_ENV: test
 
 compose:
   files: