tests: move makeInterest/makeData/etc to ndn::tests namespace

refs #2376

Change-Id: If824388f1e2859d7d2199cd622db2aa1a3277798
diff --git a/tests/unit-tests/mgmt/status-dataset-context.t.cpp b/tests/unit-tests/mgmt/status-dataset-context.t.cpp
index d7c0716..b1876db 100644
--- a/tests/unit-tests/mgmt/status-dataset-context.t.cpp
+++ b/tests/unit-tests/mgmt/status-dataset-context.t.cpp
@@ -27,6 +27,8 @@
 namespace mgmt {
 namespace tests {
 
+using namespace ndn::tests;
+
 class StatusDatasetContextFixture
 {
 public:
@@ -39,7 +41,7 @@
   };
 
   StatusDatasetContextFixture()
-    : interest(util::makeInterest("/test/context/interest"))
+    : interest(makeInterest("/test/context/interest"))
     , contentBlock(makeStringBlock(tlv::Content, "/test/data/content"))
     , context(*interest,
               [this] (const Name& dataName, const Block& content,