Fix typo that cause AWS auth to fail. (#7)

Author: Arthur Cinader

lib/transfer.js

@@ -47,7 +47,7 @@ function _setup() {
     });
   } else if (config.transferTo == 's3') {
     config.filesAdapter = new S3Adapter({
-      accessKey: config.aws_secretAccessKey,
+      accessKey: config.aws_accessKeyId,
       secretKey: config.aws_secretAccessKey,
       bucket: config.aws_bucket,
       bucketPrefix: config.aws_bucketPrefix,