fix typo and remove DS_Store

.github/workflows/go.yml

@@ -16,10 +16,10 @@ jobs:
     - name: Set up Go
       uses: actions/setup-go@v2
       with:
-        go-version: 1.15
+        go-version: 1.16
 
     - name: Build
-      run: go build -v ./*
+      run: go build -v ./*.go
 
     - name: Test
       run: go test -v ./...