Added missing system libraries and headers for bazel.

Change-Id: I966d28dd5a6677acc73c608a89efa30f8358b0dd
diff --git a/y2014/control_loops/shooter/BUILD b/y2014/control_loops/shooter/BUILD
index 2007973..8013afc 100644
--- a/y2014/control_loops/shooter/BUILD
+++ b/y2014/control_loops/shooter/BUILD
@@ -43,6 +43,7 @@
     '//y2014:constants',
     '//frc971/control_loops:state_feedback_loop',
     '//aos/common/logging:queue_logging',
+    '//external:libm',
   ],
 )