Update Test.yml

Author: kareman

.github/workflows/Test.yml

@@ -18,7 +18,7 @@ jobs:
     - name: Checkout
       uses: actions/checkout@v2
     - name: Set Swift version
-      if: matrix.os == "ubuntu-18.04"
+      if: matrix.os == 'ubuntu-18.04'
       run: echo "5.3-DEVELOPMENT-SNAPSHOT-2020-08-08-a" > .swift-version
     - name: Install Swift
       uses: YOCKOW/Action-setup-swift@master