Add J and Mass to drivetrain_config

They are needed for trajectory planning.

Change-Id: I8daf4303fee347af77567b20078f597354ba2472
diff --git a/y2014/control_loops/drivetrain/drivetrain_base.cc b/y2014/control_loops/drivetrain/drivetrain_base.cc
index 8859f16..be4f238 100644
--- a/y2014/control_loops/drivetrain/drivetrain_base.cc
+++ b/y2014/control_loops/drivetrain/drivetrain_base.cc
@@ -37,6 +37,8 @@
 
       constants::GetValues().high_gear_ratio,
       constants::GetValues().low_gear_ratio,
+      drivetrain::kJ,
+      drivetrain::kMass,
       constants::GetValues().left_drive.shifter_hall_effect,
       constants::GetValues().right_drive.shifter_hall_effect,
       true /* default_high_gear */,