Shell test(s) for integration testing

[mtrofin]

Do we want something more formal for shell tests - we have check_license.sh but not much else, but there are cases where we'd want to test a tool (for example, PR #357 ) with e.g. saved_model_cli and then maybe a few more steps (like building a small C/C++ example, etc)

At minimum we can run such scripts from the CI, of course, but having a nice test infra for shells would help.

[boomanaiden154]

This was sort of the goal in #121.

[mtrofin]

ack, but can we have a shell test framework (like are there such things - do we need one... that kind of thing. Something to know to keep running all tests even if one fails, manage scratch dirs... I'm hoping we can get something off the shelf.)