Moved DrivetrainWriter from y2014

Change-Id: I168b901e0bdc21668344c8003820ac9ff77f4c0b
diff --git a/y2014/BUILD b/y2014/BUILD
index d83a477..bf8f689 100644
--- a/y2014/BUILD
+++ b/y2014/BUILD
@@ -93,6 +93,7 @@
         "//frc971/wpilib:buffered_pcm",
         "//frc971/wpilib:dma",
         "//frc971/wpilib:dma_edge_counting",
+        "//frc971/wpilib:drivetrain_writer",
         "//frc971/wpilib:encoder_and_potentiometer",
         "//frc971/wpilib:gyro_sender",
         "//frc971/wpilib:interrupt_edge_counting",