tests: Improving ManagementTool test suite and fixing discovered bugs

Change-Id: I1c7e51cf105544325657825474f9ee85d61396ed
Refs: #2226
diff --git a/tests/unit/mgmt/.ndn/client.conf b/tests/unit/mgmt/.ndn/client.conf
new file mode 100644
index 0000000..da43a84
--- /dev/null
+++ b/tests/unit/mgmt/.ndn/client.conf
@@ -0,0 +1,2 @@
+tpm=file
+