fixed package imports

related to issue #27

porder/async_down.py

@@ -1,6 +1,23 @@
+__copyright__ = """
+    Copyright 2019 Samapriya Roy
+    Licensed under the Apache License, Version 2.0 (the "License");
+    you may not use this file except in compliance with the License.
+    You may obtain a copy of the License at
+       http://www.apache.org/licenses/LICENSE-2.0
+    Unless required by applicable law or agreed to in writing, software
+    distributed under the License is distributed on an "AS IS" BASIS,
+    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+    See the License for the specific language governing permissions and
+    limitations under the License.
+"""
+__license__ = "Apache 2.0"
+
 import requests
 import asyncio
 import os
+import progressbar
+import sys
+import time
 from concurrent.futures import ThreadPoolExecutor
 from timeit import default_timer
 from retrying import retry