Add example build test

.github/workflows/build-and-test-alpha.yml

@@ -37,6 +37,17 @@ jobs:
         working-directory: ./v3
         run: go test -v ./...
 
+      - name: Run go build for each subdirectory in v3/examples
+        run: |
+          for dir in *
+          do 
+            dir=${dir%*/}
+            echo "Building $dir"
+            cd $dir
+            go build $dir
+            cd -
+          done
+
       - name: Run tests (!mac)
         if: matrix.os != 'macos-latest'
         working-directory: ./v3