Test library for testing single conflict cases

[jjohannes]

The samples/sample-all is a nice thing to test that in combination everything gives a valid result.

However, not all conflict situation can be produced together in a single dependency graph.

I could imagine to have a test setup (abstract test super class or test fixture code) where you can then write tests only providing the following:

Conflict with automatic resolution:

dependencies:
...
...

expected selected dependencies:
...
...

Conflict without solution:

dependencies:
...
...

expected conflict:
...