Destroys Change Management Record when destroying Software Record.

[scherztc]

Fixes #336

[hortongn]

@scherztc I think it would be worth updating this exiting SoftwareRecord delete test to verify that it deletes an attached change request with the software record:
https://github.com/uclibs/application_portfolio/blob/qa/spec/controllers/software_records_controller_spec.rb#L396-L401

[scherztc]

The Software Record delete test has been updated to account for the ChangeRequest.

[hortongn]

@scherztc You need an expect statement that verifies the change request has been deleted.

[scherztc]

@hortongn : Initially, I thought that the SoftwareRecord test was enough, since it wouldn't actually pass if our code was wrong. After your feedback, I added another test that also checks for the deletion of the ChangeRequest. It should be good, now.

[hortongn]

@scherztc Thanks for adding the test!