Retune drivetrain closed loop controller to be more rigid

Significantly faster convergance.  Slight overshoot on steering, but
it's only gear chattering, no real physical overshoot.

Change-Id: I56bc3b51835dc68579e24178af837858c6352af3
diff --git a/y2019/control_loops/python/drivetrain.py b/y2019/control_loops/python/drivetrain.py
index 6a1da4e..4a68fde 100644
--- a/y2019/control_loops/python/drivetrain.py
+++ b/y2019/control_loops/python/drivetrain.py
@@ -24,8 +24,8 @@
     robot_radius=0.45 / 2.0,
     wheel_radius=4.0 * 0.0254 / 2.0,
     G=9.0 / 52.0,
-    q_pos=0.17,
-    q_vel=1.65,
+    q_pos=0.14,
+    q_vel=1.30,
     efficiency=0.80,
     has_imu=True,
     force=True,