.github/workflows/ci.yml in mini_portile2-2.5.1 vs .github/workflows/ci.yml in mini_portile2-2.5.2

@@ -15,10 +15,10 @@
     env:
       MAKEFLAGS: -j2
     strategy:
       matrix:
         platform: [ubuntu-latest, windows-latest]
-        ruby: ["2.5", "2.6", "2.7", "3.0"]
+        ruby: ["2.3", "2.4", "2.5", "2.6", "2.7", "3.0", "head"]
     runs-on: ${{ matrix.platform }}
     steps:
       - name: configure git crlf on windows
         if: matrix.platform == 'windows-latest'
         run: |