Add code coverage

* add coverage for all lines within LossViewer.update_runtime()

tests/gui/test_monitor.py

@@ -1,9 +1,35 @@
+from turtle import title
 from sleap.gui.widgets.monitor import LossViewer
+from sleap import TrainingJobConfig
 
 
-def test_monitor_release(qtbot):
+def test_monitor_release(qtbot, min_centroid_model_path):
     win = LossViewer()
     win.show()
+
+    # Ensure win loads config correctly
+    config = TrainingJobConfig.load_json(min_centroid_model_path, False)
+    win.reset(what="Model Type", config=config)
+    assert win.config.optimization.early_stopping.plateau_patience == 10
+
+    # Ensure all lines of update_runtime() are run error-free
+    win.is_running = True
+    win.t0 = 0
+    # Enter "last_epoch_val_loss is not None" conditional
+    win.last_epoch_val_loss = win.config.optimization.early_stopping.plateau_min_delta
+    # Enter "penultimate_epoch_val_loss is not None" conditional
+    win.penultimate_epoch_val_loss = win.last_epoch_val_loss
+    win.mean_epoch_time_min = 0
+    win.mean_epoch_time_sec = 10
+    win.eta_ten_epochs_min = 2
+    # Enter "epoch_in_plateau_flag" conditional
+    win.epoch_in_plateau_flag = True
+    win.epochs_in_plateau = 1
+    # Enter "bes_val_x" conditional
+    win.best_val_x = 0
+    win.best_val_y = win.last_epoch_val_loss
+    win.update_runtime()
+
     win.close()
 
     # Make sure the first monitor released its zmq socket