Re-enable unit test

Unit test were broken after sd bus calls started throwing exception,
In this repo we start the systemd-networkd with the use of sd bus
calls, which throws exception and it was not handled in the test case.

This commit fixes the problem by mocking the network manager which
mock the functionality of function which makes the sdbus call.

Change-Id: I5b60a2117a661cffa36200415ca611b85dd2fda1
Signed-off-by: Ratan Gupta <ratagupt@linux.vnet.ibm.com>
diff --git a/Makefile.am b/Makefile.am
index fa3f92b..43f4643 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -99,4 +99,4 @@
 	$(SDBUSPLUSPLUS) -r $(srcdir) interface server-header xyz.openbmc_project.Network.IP.Create > $@
 	sed -i '5i #include \"xyz\/openbmc_project\/Network\/IP\/server.hpp\"' $@
 
-#SUBDIRS = test
+SUBDIRS = test