Google App Engine python-flask-codelab Has Some Version Issues

Codelab python-flask-codelab fails firstly due to a grcpio version issue which means the build exceeds the 10 minute timeout
see https://groups.google.com/forum/#!topic/google-appengine/2YMjSDx8y_I

Then the issue is the google-api-core version: ‘grpc.experimental.aio’ has no attribute ‘StreamUnaryCall’
See https://github.com/googleapis/python-api-core/issues/40

Solution was to add these two lines to requirements,txt then rebuild and redeploy

grpcio==1.27.2

google-api-core==1.16.0