Add Github Action workflow for building and testing

[cmur2]

This is just a humble proposal to allow contributors and maintainers to quickly check whether contributions work as advertised (running 'make clean test integration`) without involving a local machine.

You can find a demo on how this would look like at my fork: https://github.com/cmur2/container-diff/pull/1

I guess for https://github.com/GoogleContainerTools/container-diff it's disabled to run actions of first time contributors orso, see repository settings.

I also included fixes to allow successful builds with the most recent Go stable release (1.17) which includes the noteworthy https://go.googlesource.com/proposal/+/master/design/draft-gobuild.md