.travis.yml in imap-backup-2.2.1 vs .travis.yml in imap-backup-2.2.2

@@ -2,13 +2,13 @@
 
 services:
   - docker
 
 rvm:
-  - 2.3
   - 2.4
   - 2.5
   - 2.6
+  - 2.7
   - jruby-19mode
 
 branches:
   only:
     - master