ci.yml in openxml-docx-0.11.4

- old
+ new

@@ -5,10 +5,10 @@
   ruby:
     name: Ruby Tests
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        ruby-version: [ "2.6", "2.7" ]
+        ruby-version: [ "2.6", "2.7", "3.0" ]
 
     steps:
       - name: Checkout
         uses: actions/checkout@v2
       - name: Setup Ruby