shill: Add unit tests for RTNLListener.

BUG=chromium-os:17394
TEST=unit tests

Change-Id: I2b68d24d14ff11c9c071c4321790a9214e7d7997
Reviewed-on: http://gerrit.chromium.org/gerrit/3819
Reviewed-by: Darin Petkov <petkov@chromium.org>
Tested-by: Darin Petkov <petkov@chromium.org>
diff --git a/Makefile b/Makefile
index 4327776..69a5558 100644
--- a/Makefile
+++ b/Makefile
@@ -112,6 +112,7 @@
 	profile_unittest.o \
 	property_accessor_unittest.o \
 	property_store_unittest.o \
+	rtnl_listener_unittest.o \
 	service_unittest.o \
 	shill_unittest.o \
 	testrunner.o \