build: enable valgrind

Enable valgrind tests.

Change-Id: Ib5ec22a19c043ef45f5274e4716e2abbae9c19da
Signed-off-by: Patrick Venture <venture@google.com>
diff --git a/test/Makefile.am b/test/Makefile.am
index a1dfba5..86cfad1 100644
--- a/test/Makefile.am
+++ b/test/Makefile.am
@@ -1,3 +1,4 @@
+@VALGRIND_CHECK_RULES@
 @CODE_COVERAGE_RULES@
 
 AM_CPPFLAGS = \