Test examples in CI.

[ekr-cfa]

We do run cargo test --examples, but it doesn't test main

[RobertJacobsonCDC]

PR #214 addresses this.

Cargo doesn't have a single command to run all examples, but you can get cargo to give you a list of all examples. One of the examples requires command line arguments, so really it's just as easy to list them out in a script.

We could list out every example in build-test.yaml instead of referencing the "run examples" script, but it's nice to have a script locally as well.