Updating workflow scripts

[rmbielby]

Pull request overview

I've updated the following workflows in line with current standard:

• deploy-shiny.yaml
• tidy-code.yaml
• shiny-tests.yaml

As part of this I've also created some basic shiny tests so that the script has something to check.

Pull request checklist

Please check if your PR fulfils the following:

• Tests for the changes have been added (for bug fixes / features)
• Docs have been reviewed and added / updated if needed (for bug fixes / features)
• Tests have been run locally and are passing (run_tests_locally())
• Code is styled according to tidyverse styling (checked locally with tidy_code())

What is the current behaviour?

Workflow scripts are a little out of date.

What is the new behaviour?

Deploy scripts should now all work.

Anything else