TST: Fix increment in risk test that drops leading values.

The leading date of the date range was never called with update,
because in the main loop the todays_date variable was
incremented before update was called.

Fix by moving the increment to the next trading day to after the
call to update.

tests/test_risk_compare_batch_iterative.py

@@ -78,9 +78,6 @@ class RiskCompareIterativeToBatch(unittest.TestCase):
             )
             cur_returns.append(todays_return_obj)
 
-            # Move forward day counter to next trading day
-            todays_date = trading.environment.next_trading_day(todays_date)
-
             try:
                 risk_metrics_original = risk.RiskMetricsBatch(
                     start_date=start_date,
@@ -103,6 +100,9 @@ class RiskCompareIterativeToBatch(unittest.TestCase):
                 ret,
                 self.all_benchmark_returns[todays_return_obj.date])
 
+            # Move forward day counter to next trading day
+            todays_date = trading.environment.next_trading_day(todays_date)
+
             self.assertEqual(
                 risk_metrics_original.start_date,
                 risk_metrics_refactor.start_date)