Add hrjob entities to api_v3_HRJobTest::testCreateChained

hrjob includes several new entities (with XML/DAO/BAO/API). Although api_v3_SyntaxConformanceAllEntitiesTest should do the heavy-lifting of testing these, we need some basic sanity tests to ensure that the API's are working and fitting together.

This commit adds a test-case for creating an HRJob record and an HRJobPay record:

https://github.com/civicrm/civihr/commit/2a9aa79cc0883ede91e8377b583c6edf9831d8ef

Using HRJobPay as a model, we should update the test to create records with every other HRJob* API.

See also:

• http://wiki.civicrm.org/confluence/display/CRMDOC43/Create+a+Module+Extension#CreateaModuleExtension-Addaunit-testclass
• https://github.com/civicrm/civihr/blob/master/README.md ("Test")