More flexible project structure

[stefanbschneider]

Don't enforce a fixed structure of certain folders, but allow any structure as long as the files are added to the project.yml

[stefanbschneider]

The idea is to list all involved files in project.yml. The files can be anywhere within the project folder. This is highly related to issues #8 and #9. @mpeuster Should we still generate the same old folder structure of dependencies, deployment, sources and automatically add the generated files to project.yaml? Or just create a sample NSD and VNFD inside the project folder without all the subfolders and other files?

[stefanbschneider]

Agreed to keep generating the folder structure as suggested best practice but also allow adding files from anywhere inside the project.