Add single speed robot option to DrivetrainParams

It just forces high and low to have the same ratio, but then we can
change this in the future easier.

Change-Id: I7011703d5f0800638bc285d9da75b03342bc602c
diff --git a/y2017/control_loops/python/drivetrain.py b/y2017/control_loops/python/drivetrain.py
index 74b114d..50a5a1c 100755
--- a/y2017/control_loops/python/drivetrain.py
+++ b/y2017/control_loops/python/drivetrain.py
@@ -10,29 +10,29 @@
 
 gflags.DEFINE_bool('plot', False, 'If true, plot the loop response.')
 
-kDrivetrain = drivetrain.DrivetrainParams(J = 6.0,
-                                          mass = 52,
-                                          robot_radius = 0.59055 / 2.0,
-                                          wheel_radius = 0.08255 / 2.0,
-                                          G_high = 11.0 / 60.0,
-                                          G_low = 11.0 / 60.0,
-                                          q_pos_low = 0.12,
-                                          q_pos_high = 0.14,
-                                          q_vel_low = 1.0,
-                                          q_vel_high = 0.95,
-                                          has_imu = False)
+kDrivetrain = drivetrain.DrivetrainParams(
+    J=6.0,
+    mass=52,
+    robot_radius=0.59055 / 2.0,
+    wheel_radius=0.08255 / 2.0,
+    G=11.0 / 60.0,
+    q_pos_low=0.12,
+    q_pos_high=0.14,
+    q_vel_low=1.0,
+    q_vel_high=0.95,
+    has_imu=False)
 
 def main(argv):
-  argv = FLAGS(argv)
-  glog.init()
+    argv = FLAGS(argv)
+    glog.init()
 
-  if FLAGS.plot:
-    drivetrain.PlotDrivetrainMotions(kDrivetrain)
-  elif len(argv) != 5:
-    print "Expected .h file name and .cc file name"
-  else:
-    # Write the generated constants out to a file.
-    drivetrain.WriteDrivetrain(argv[1:3], argv[3:5], 'y2017', kDrivetrain)
+    if FLAGS.plot:
+        drivetrain.PlotDrivetrainMotions(kDrivetrain)
+    elif len(argv) != 5:
+        print "Expected .h file name and .cc file name"
+    else:
+        # Write the generated constants out to a file.
+        drivetrain.WriteDrivetrain(argv[1:3], argv[3:5], 'y2017', kDrivetrain)
 
 if __name__ == '__main__':
-  sys.exit(main(sys.argv))
+    sys.exit(main(sys.argv))