code: function (prefix, s3, callback) {
          if (!s3.client || !s3.bucket) {
              grunt.warn("Error: No client or bucket name defined.");
          }
          // List all of the objects in the bucket starting with prefix.
          var options = {BucketName : s3.bucket, Prefix: prefix || ''};
          s3.client.ListObjects(options, function(err, data) {
              if (err) {
                  var message = (err.Body && err.Body.Error && err.Body.Error.Message) || 'Unknown';
                  return callback({message: "Could not fetch bucket objects. " + message});
              }
              var bucketContents = data.Body.ListBucketResult.Contents;
  
              callback(null, bucketContents);
          });
      }
docs: ## getBucketObjects Gets a listing of objects in an S3 bucket, with an optional prefix.