fix(video.py): return self instead of video_meta_file

fix(main.py): print video object instead of video url
feat(uploader.py): add retry mechanism to handle token expiration and refresh token if necessary. Also, pass youtube object to upload_thumbnail function.

main.py

@@ -64,7 +64,7 @@ async def main():
     video = await channel.generate_video(idea)
     printm("Done!")
     printm("Here is the video:")
-    printm(video.url)
+    printm(video)
 if __name__ == "__main__":
     loop = asyncio.get_event_loop()
     loop.run_until_complete(main())