Terratest lambda cloudwatch trigger

[alasseter-dds]

@pjdufour-dds when you get the chance can you take a look at this branch. working to set up terratest module for a scheduled lambda function based on these examples:

• https://registry.terraform.io/modules/USSBA/scheduled-lambda/aws/latest
• https://github.com/USSBA/terraform-aws-scheduled-lambda/blob/v2.1.0/examples/simple/main.tf

I'm uncertain about the following:

• starting from the simple-test branch as a baseline, I think the only two files that need updating are _test.go and main.tf -- is it also necessary to update handler.py? (I think not)
• I believe that _test.go requires just a few updates, and I think I've made them successfully but would love your feedback.
• The blocker for me is main.tf -- lots of stuff in the examples I linked above don't seem to translate. For example, lambda_iam_policy is supposed to be required in data but we don't seem to be using it in our terratest modules. I don't get that.

[alasseter-dds]

I updated this branch with the latest PR to master, so it now reflects the most up-to-date changes in module-template.