Fixed building with a bazel with hdrs_check fixed again.

Change-Id: I015f66cd6e02e07efa367b96edd775015ac0abca
diff --git a/y2015/util/BUILD b/y2015/util/BUILD
index e520d5d..481ed7e 100644
--- a/y2015/util/BUILD
+++ b/y2015/util/BUILD
@@ -2,6 +2,9 @@
 
 cc_library(
   name = 'kinematics',
+  hdrs = [
+    'kinematics.h',
+  ],
   deps = [
     '//third_party/eigen',
     '//y2015:constants',