.travis.yml in autobuild-1.20.0 vs .travis.yml in autobuild-1.21.0

@@ -2,9 +2,11 @@
 language: ruby
 rvm:
   - '2.3'
   - '2.4'
   - '2.5'
+  - '2.6'
+  - '2.7'
   - 'jruby-9.1.15.0'
 matrix:
     allow_failures:
         - rvm: 'jruby-9.1.15.0'