SqlServerDsc: Integration test should also run tests using SqlServer module

[johlju]

Details of the scenario you tried and the problem that is occurring:
Integration tests should run tests using the SqlServer PowerShell module on top of testing using SQLPS PowerShell module.

This is relevant to issue #509 as well.

The DSC configuration that is using the resource (as detailed as possible):
n/a

Version of the Operating System, SQL Server and PowerShell the DSC Target Node is running:
n/a

What module (SqlServer or SQLPS) and which version of the module the DSC Target Node is running:
SqlServer

Version of the DSC module you're using, or 'dev' if you're using current dev branch:
Dev