RA-343: Include Process HL7 task

https://issues.openmrs.org/browse/RA-343

Added a method that adds Process HL7 task when module is started.
This should not extend BaseModuleContextSensitiveTest. The idea is that you're doing a lightweight, faster-to-run test that does _not_ look at the context, but properly unit tests just a specific piece of code, rather than integration-testing the whole application.