Figure out how to share some of YAML files

[rsvoboda]

Figure out how to share some of YAML files.
We have duplicates on several places in the repository.

Pointed out in #28 (comment)

[Sgitario]

I can see a couple of straight-forward solutions to manage shared YAML files:

• Using a shared Maven module:

Good: Easy to use as resources will still be part of the classpath
Bad: Modules will depend on this new module (they depend on a common module already)

• Using a common folder:

Good: Modules won't depend to any new Maven module
Bad: We'll rely on relative paths to resolve the resources...

What do you think? @rsvoboda @Ladicek

[Ladicek]

I think a shared module is fine. I guess we could actually use the common module, which mostly contains the test framework, but can easily contain shared resources as well.