junit reporters run function never call the callback param

the third param of the junit reporter's run method is a callback. that call back function is never actually called.

The other reporters don't actually accept a callback, but they should.

Locate the JUnit reporter's run method and compare it with the run methods in the other reporters. Trace how each reporter is invoked, then make callback handling consistent so the supplied callback is called; done means all reporters accept and invoke callbacks as expected.

Written by the indexing model from the issue text.