.travis.yml in vips-8.8.4 vs .travis.yml in vips-8.9.1

@@ -39,9 +39,10 @@
     - rvm: 2.5
     - rvm: 2.6
     - rvm: 2.6
       os: osx
       env: PKG_CONFIG_PATH="/usr/local/opt/libffi/lib/pkgconfig"
+    - rvm: 2.7
     - rvm: truffleruby
     - rvm: jruby-head
     - rvm: ruby-head
   allow_failures:
     - rvm: truffleruby