build: enable valgrind

Enable valgrind to check memory usage.

Change-Id: I0d1e5d72b713819d125e365b33c4bc4f58890f73
Signed-off-by: Patrick Venture <venture@google.com>
diff --git a/test/Makefile.am b/test/Makefile.am
index b9ad829..08b5a1c 100644
--- a/test/Makefile.am
+++ b/test/Makefile.am
@@ -1,3 +1,5 @@
+@VALGRIND_CHECK_RULES@
+
 AM_CPPFLAGS = \
 	-I$(top_srcdir)/ \
 	$(GTEST_CFLAGS) \