Add J and Mass to drivetrain_config

They are needed for trajectory planning.

Change-Id: I8daf4303fee347af77567b20078f597354ba2472
diff --git a/motors/simple_receiver.cc b/motors/simple_receiver.cc
index 91e2229..a78f1e0 100644
--- a/motors/simple_receiver.cc
+++ b/motors/simple_receiver.cc
@@ -76,7 +76,10 @@
       ::motors::seems_reasonable::kWheelRadius, ::motors::seems_reasonable::kV,
 
       ::motors::seems_reasonable::kHighGearRatio,
-      ::motors::seems_reasonable::kLowGearRatio, kThreeStateDriveShifter,
+      ::motors::seems_reasonable::kLowGearRatio,
+      ::motors::seems_reasonable::kJ,
+      ::motors::seems_reasonable::kMass,
+      kThreeStateDriveShifter,
       kThreeStateDriveShifter, true /* default_high_gear */,
       0 /* down_offset if using constants use
                                    constants::GetValues().down_error */, 0.8 /* wheel_non_linearity */,