Add new tests to presubmit, fix errors

ct/go/util/gs.go

 // Google Storage utility that contains methods for both CT master and worker
 // scripts.
 package util
 
 import (
         "fmt"
         "io"
         "io/ioutil"
         "net/http"
         "os"
@@ skipping 122 matching lines @@
         req := gs.service.Objects.List(GS_BUCKET_NAME).Prefix(gsDir + "/")
         for req != nil {
                 resp, err := req.Do()
                 if err != nil {
                         return fmt.Errorf("Error occured while listing %s: %s", gsDir, err)
                 }
                 for _, result := range resp.Items {
                         fileName := filepath.Base(result.Name)
 
                         wg.Add(1)
-                        go func() {
+                        go func(result *storage.Object) {
                                 defer wg.Done()
                                 respBody, err := getRespBody(result, gs.client)
                                 if err != nil {
                                         glog.Errorf("Could not fetch %s: %s", result.MediaLink, err)
                                         return
                                 }
                                 defer respBody.Close()
                                 outputFile := filepath.Join(localDir, fileName)
                                 out, err := os.Create(outputFile)
                                 if err != nil {
                                         glog.Errorf("Unable to create file %s: %s", outputFile, err)
                                         return
                                 }
                                 defer out.Close()
                                 if _, err = io.Copy(out, respBody); err != nil {
                                         glog.Error(err)
                                         return
                                 }
                                 glog.Infof("Downloaded gs://%s/%s to %s", GS_BUCKET_NAME, result.Name, outputFile)
-                        }()
+                        }(result)
                 }
                 if len(resp.NextPageToken) > 0 {
                         req.PageToken(resp.NextPageToken)
                 } else {
                         req = nil
                 }
         }
         wg.Wait()
         return nil
 }
@@ skipping 66 matching lines @@
                         if err != nil {
                                 glog.Errorf("Objects.Insert failed: %s", err)
                                 return
                         }
                         glog.Infof("Created object %s at location %s", res.Name, res.SelfLink)
                 }()
         }
         wg.Wait()
         return nil
 }