Should create a "slimmer" runtime docker image

My suggestion is to create another image that is designed for runtime (no compilation/SDK components). Right now the OpenTAP Docker image is 2.65 GB in size. With a couple changes, I was able to shrink it down to about 440 MB. The changes were fairly straightforward:

# give the first line a label
FROM ubuntu:18.04 as builder

. . .

# then at the bottom create a release image, based off of the Microsoft ASP.NET Core Runtime bionic image (Ubuntu 18.04 based still), and then just copy over the TAP files and set permissions, environment variables...

FROM mcr.microsoft.com/dotnet/core/aspnet:2.1.12-bionic as release

COPY --from=builder /opt/tap /opt/tap
RUN chmod -R +w /opt/tap
RUN chmod +x /opt/tap/tap
ENV PATH="/opt/tap:${PATH}"
ENV TAP_PATH="/opt/tap"