.travis.yml in jekyll-gzip-2.2.0 vs .travis.yml in jekyll-gzip-2.3.0

@@ -4,11 +4,16 @@
   - 2.6
   - 2.5
   - 2.4
   - 2.3
   - ruby-head
+env:
+  - 'JEKYLL_VERSION="~> 3.0"'
+  - 'JEKYLL_VERSION="~> 4.0"'
 matrix:
   allow_failures:
     - rvm: ruby-head
-
+  exclude:
+    - rvm: 2.3
+      env: 'JEKYLL_VERSION="~> 4.0"'
 before_install: gem install bundler
-script: bundle exec rspec
\ No newline at end of file
+script: bundle exec rspec