Change #include style

Header files are now always included with their path from the
project's root directory rather than the path relative to
the includer.

Change-Id: If39b8510eef8da00baf5fe88337c45dbdf8c766e
Refs: #3084
diff --git a/tests/unit/packet-base.t.cpp b/tests/unit/packet-base.t.cpp
index 8b4dfa2..d541512 100644
--- a/tests/unit/packet-base.t.cpp
+++ b/tests/unit/packet-base.t.cpp
@@ -19,11 +19,11 @@
  * See AUTHORS.md for complete list of ndn-cxx authors and contributors.
  */
 
-#include "packet-base.hpp"
+#include "ndn-cxx/packet-base.hpp"
+#include "ndn-cxx/interest.hpp"
+#include "ndn-cxx/lp/tags.hpp"
 
-#include "../boost-test.hpp"
-#include "interest.hpp"
-#include "lp/tags.hpp"
+#include "tests/boost-test.hpp"
 
 namespace ndn {
 namespace tests {