Plugin doesn't support nested submodules

[vashchenkov]

I have three levels of modules in project

/parent
     /integration
         /api

And I try to send report to SonarCube. I define modules like this

server, integration/api

And I've got error

ERROR: Caused by: Validation of project reactor failed:
o "xxxx:parent:integration/api" is not a valid project or module key. Allowed characters are alphanumeric, '-', '_', '.' and ':', with at least one non-digit.

If i define modules like

server, integration.api

I've got an error

 Caused by: The base directory of the module 'integration.api' does not exist: /work/buildagent/work/4378ba1d8b2684e8/./integration.api

Is it possible to define nested modules?