Uninstall typing for smdebug version bump

[edwardjkim]

Description of changes:

sagemaker-containers (which is deprecated) installs typing which was necessary in Python 3.5 for typing support but is no longer necessary in Python 3.7. Install typing in Python 3.7 can result in conflicts, e.g., when installing python3 -m pip install black. The simplest solution is to uninstall typing at the end.

By submitting this pull request, I confirm that you can use, modify, copy, and redistribute this contribution, under the terms of your choice.

[edwardjkim]

We are hitting docker pull rate limit:

Step 4/23 : FROM nvidia/cuda:${CUDA_VERSION}-base-ubuntu${UBUNTU_VERSION}@sha256:${IMAGE_DIGEST}
toomanyrequests: You have reached your pull rate limit. You may increase the limit by authenticating and upgrading: https://www.docker.com/increase-rate-limit