fix test

Author: sshane

selfdrive/test/longitudinal_maneuvers/plant.py

@@ -131,6 +131,7 @@ def step(self, v_lead=0.0, prob=1.0, v_cruise=50.):
       "distance": self.distance,
       "speed": self.speed,
       "acceleration": self.acceleration,
+      "speeds": self.speeds,
       "distance_lead": self.distance_lead,
       "fcw": fcw,
     }