ci.yaml in danger-jacoco-0.1.6

- old
+ new

@@ -6,7 +6,8 @@
     steps:
       - uses: actions/checkout@v1
       - uses: actions/setup-ruby@v1
         with:
           ruby-version: '2.6.x'
+      - run: gem install bundler
       - run: bundle install
       - run: bundle exec rake spec