Do some more involved testing in CI

[NoxHarmonium]

The CI script at the moment just packages each example project. It proves that the plugin compiles and that the example projects don't throw any errors but it doesn't really test any assertions.

We should probably write some tests that check that the generated CF looks correct and that the lambda bundles contain the right files.

We could also use the deploy-all/verify-all scripts (or something similar) to actually deploy the examples somewhere and check that they work IRL

[NoxHarmonium]

I've started working on this. It's in a branch (https://github.com/agiledigital-labs/aws-durable-lambda/tree/issue-43-int-test) , its mostly there I just need to work out a good IAM policy to assign the role that Github actions uses to deploy the example projects. I have a sandbox AWS account I can use, I'm just hesitant to give the role full admin access to the environment.