Can not find source for tensorflow and torch package about ossgadget

[gaokai320]

PR #399 fixes this issue. I test it with docker. I can successfully build the docker image and find the source code repository for tensorflow and torch package.

root@d1049957475e:~# oss-find-source pkg:pypi/tensorflow pkg:pypi/torch

   ____   _____ _____    _____           _            _
  / __ \ / ____/ ____|  / ____|         | |          | |
 | |  | | (___| (___   | |  __  __ _  __| | __ _  ___| |_
 | |  | |\___ \\___ \  | | |_ |/ _` |/ _` |/ _` |/ _ \ __|
 | |__| |____) |___) | | |__| | (_| | (_| | (_| |  __/ |_
  \____/|_____/_____/   \_____|\__,_|\__,_|\__, |\___|\__|
                                            __/ |
                                           |___/
OSS Gadget - oss-find-source 0.0.0+ebd2e46ccf - github.com/Microsoft/OSSGadget
100.0%  https://github.com/tensorflow/tensorflow (pkg:github/tensorflow/tensorflow)
100.0%  https://github.com/pytorch/pytorch (pkg:github/pytorch/pytorch)