Update workflow

Author: sinoru

.github/workflows/workflow.yml

@@ -7,7 +7,7 @@ jobs:
     strategy:
       matrix:
         operating-system: [macOS-latest]
-        xcode-version: ["10.0", "11.0", "11.1", "11.2.1"]
+        xcode-version: ["9.0", "10.0", "11.0", "11.1", "11.2.1"]
     steps:
     - uses: actions/checkout@v1
     - name: Setup Xcode
@@ -16,3 +16,4 @@ jobs:
         xcode-version: ${{ matrix.xcode-version }}
         apple-id: [email protected]
         apple-id-password: ${{ secrets.APPLE_ID_PASSWORD }}
+    - run: xcodebuild -version -sdk