[CI] Add Swift 5.10 to unit test matrix (#20)

Author: slashmo

.github/workflows/ci.yml

@@ -24,7 +24,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        swift: [5.9, latest]
+        swift: ["5.9", "5.10", "latest"]
 
     steps:
       - name: Install Swift