[Concurrency] scoverage-maven-plugin is not thread safe

[harrysingh]

When running build for multi module project, maven complains for scoverage-maven-plugin not being thread safe

 [WARNING] The following plugins are not marked @threadSafe in <module name>:
 [WARNING] org.scoverage:scoverage-maven-plugin:1.4.1
 [WARNING] Enable debug to see more precisely which goals are not marked @threadSafe.
 [WARNING] *****************************************************************

Also, when project is run with parallelism, aggregation either fails or is incorrect.

P.S. When running with no parallelism, module data is aggregated correctly.

[RPCMoritz]

Duplicates #83 ?

[jozic]

closing as duplicate of #83
@harrysingh please comment if you believe it's not a duplicate