Introduce deptrac

[DavidLambauer]

Introduce deptrac to detect potential architecture flaws right up front.

https://github.com/qossmic/deptrac

An example rule could be disallowing access to other modules without using the proper interfaces.

[memegento-dev]

We prepared a simple script that generates layers config for each module based on its module.xml into deptrac.layers.yaml
Then by running ./deptrac missing dependencies can be found. Looks like all used modules must be explicitly defined in module.xml

The script and deptrac.layers.yaml.dist can be found in our example repo.

https://github.com/memegento/magetrac

UPD: probably replacing generating yaml with direct configuring deptrac via php config would be a better