Add script to generate and aggregate all *.adoc content into a single PDF about devops-workshop

You can do this very easily with asciidoctor-pdf, but you might want to revisit your files and structure - because AsciiDoctor does not work well with relative images referenced in documents in subdirectories.

I propose:

labs/
labs/devops-workshop-lab-guide.adoc
labs/lab-introduction.adoc
labs/00-introduction_to_cli.adoc
labs/01-building_a_spring_boot_application.adoc
labs/02-adding_persistence_to_boot_application.adoc
labs/03-enhancing_boot_application_with_metrics.adoc
labs/04-adding_spring_cloud_config_to_boot_application.adoc
labs/05-adding_service_registration_and_discovery_with_spring_cloud.adoc
labs/06-employing_a_circuit_breaker.adoc
labs/images/... all the images here
....

Then you can simply just stitch them all together in a single asciidoc document, e.g. labs/devops-workshop-lab-guide.pdf

What do you say?

[pacphi]

Thanks @nevenc-pivotal! Your PR was merged! See c8d86cc