Added code to handle wrapping values.

Change-Id: Ie6729956df08aec824a3cc9a04c5ff014a6c0909
diff --git a/frc971/zeroing/BUILD b/frc971/zeroing/BUILD
index c63d97d..0b8799f 100644
--- a/frc971/zeroing/BUILD
+++ b/frc971/zeroing/BUILD
@@ -56,3 +56,24 @@
     '//frc971/control_loops:queues',
   ],
 )
+
+cc_library(
+  name = 'wrap',
+  srcs = [
+    'wrap.cc',
+  ],
+  hdrs = [
+    'wrap.h',
+  ],
+)
+
+cc_test(
+  name = 'wrap_test',
+  srcs = [
+    'wrap_test.cc',
+  ],
+  deps = [
+    '//aos/testing:googletest',
+    ':wrap',
+  ],
+)