tests: respect naming conventions and improve nesting of some test suites

Change-Id: I255c27b552b32570871a9d5f8bda814ba8723c80
Refs: #2497
diff --git a/tests/main.cpp b/tests/main.cpp
index aa2f330..cf03e21 100644
--- a/tests/main.cpp
+++ b/tests/main.cpp
@@ -19,7 +19,7 @@
  * See AUTHORS.md for complete list of ndn-cxx authors and contributors.
  */
 
-#define BOOST_TEST_MODULE ndn-cxx Unit Tests
+#define BOOST_TEST_MODULE ndn-cxx Tests
 #define BOOST_TEST_DYN_LINK
 #define BOOST_TEST_ALTERNATIVE_INIT_API