Add changes to joystick_reader for third robot.

These were initially made by Natalia, with a lot of cleaning
up and additional changes by me.

(This was formerly a part of I3d012fb8a9652c0b85ed27f5d23fe7d63bb977ce.)

Change-Id: I23e19b7458dd8dba3b695b456917925d732c5606
diff --git a/bot3/input/input.gyp b/bot3/input/input.gyp
index 20cb7d3..aec28b7 100644
--- a/bot3/input/input.gyp
+++ b/bot3/input/input.gyp
@@ -15,6 +15,7 @@
         '<(DEPTH)/frc971/queues/queues.gyp:queues',
         '<(DEPTH)/bot3/control_loops/drivetrain/drivetrain.gyp:drivetrain_loop',
         '<(DEPTH)/bot3/autonomous/autonomous.gyp:auto_queue',
+        '<(DEPTH)/bot3/control_loops/rollers/rollers.gyp:rollers_loop',
       ],
     },
     {