ADD step to test macOS

Author: angu

.github/workflows/continous_integration.yml

@@ -16,8 +16,9 @@ jobs:
 
     steps:
     - uses: actions/checkout@v3
-    - name: Build
-      run: swift build -v
+    - name: Test macOS
+      run: | 
+        xcodebuild test -scheme SwiftAsyncAssert -destination "platform=macOS"
     - name: Test iOS
       run: | 
         xcodebuild test -scheme SwiftAsyncAssert -destination "platform=iOS Simulator,name=iPhone 13"