Update CI

Author: ctreffs

.github/workflows/ci.yml

@@ -11,7 +11,7 @@ jobs:
     runs-on: macOS-latest
     strategy:
       matrix:
-        xcode: ["11.7", "12"]
+        xcode: ["11.7", "12.2"]
     steps:
       - name: Checkout
         uses: actions/checkout@master