Added //third_party:wpilib target to aid WPILIB upgrading

Otherwise, every year, we need to edit all the targets to point to
the new WPILib.  This makes it much easier durring the beta test.

Change-Id: Ia26ef21aafe8a690242582ebfa4e391e44f8ac64
diff --git a/y2015/wpilib/BUILD b/y2015/wpilib/BUILD
index 2a5979f..fbc7535 100644
--- a/y2015/wpilib/BUILD
+++ b/y2015/wpilib/BUILD
@@ -9,7 +9,7 @@
     '//aos/linux_code:init',
     '//aos/common:stl_mutex',
     '//aos/common/logging',
-    '//third_party/allwpilib_2016:wpilib',
+    '//third_party:wpilib',
     '//y2015:constants',
     '//y2015/control_loops/drivetrain:drivetrain_queue',
     '//y2015/control_loops/fridge:fridge_queue',