Unit test for SimulationClock.iter_time_index
fluegg.simclock.SimulationClock.increment_time was removed and iter_time_index was implemented to serve the same functionality. Create unit tests for iter_time_index.
fluegg.simclock.SimulationClock.increment_time was removed and iter_time_index was implemented to serve the same functionality. Create unit tests for iter_time_index.