Add test to capture page-per-thing module

Michael added links to the more info sections recently, but they don’t
appear to render. Having a quick look at why that might be.
Remove separate VM config

There's no need for this.
Allow more flexibility when setting ports
Merge pull request #547 from alphagov/standalone-module-rendering

Add test to capture page-per-thing module
Merge pull request #550 from alphagov/update-env-variable-port

Allow more flexibility when setting ports