.travis.yml in digest-crc-0.5.1 vs .travis.yml in digest-crc-0.6.0.rc1

@@ -1,16 +1,24 @@
 ---
 before_install:
   - gem update --system
   - gem install bundler -v "~> 2.0"
+
 language: ruby
 sudo: false
 cache:
   - bundler
+
 rvm:
   - 2.5
   - 2.6
+  - 2.7
   - jruby
+
 matrix:
+  include:
+    - os: linux
+    - os: osx
   allow_failures:
     - rvm: jruby
+
 script: bundle exec rake spec