Re-tuned drivetrain steering ratio.

Change-Id: I1ccfb990667e94e6d7a3f72a7e95537a621a5f5a
diff --git a/frc971/control_loops/drivetrain/polydrivetrain.cc b/frc971/control_loops/drivetrain/polydrivetrain.cc
index 8925a40..2624483 100644
--- a/frc971/control_loops/drivetrain/polydrivetrain.cc
+++ b/frc971/control_loops/drivetrain/polydrivetrain.cc
@@ -112,7 +112,7 @@
   const bool quickturn = goal.quickturn;
   const bool highgear = goal.highgear;
 
-  const double kWheelNonLinearity = 0.4;
+  const double kWheelNonLinearity = 0.55;
   // Apply a sin function that's scaled to make it feel better.
   const double angular_range = M_PI_2 * kWheelNonLinearity;