build: align minimum build dependencies with ndn-cxx

 * boost 1.65.1
 * gcc 7.4
 * clang 6.0
 * Xcode 10.0 (11.3 or later recommended)

Also improve some test cases

Change-Id: Ib81d082a19e61940fa6f1d89204ea8de8ed57940
diff --git a/tests/update/test-prefix-update-processor.cpp b/tests/update/test-prefix-update-processor.cpp
index fe0bfac..9c20114 100644
--- a/tests/update/test-prefix-update-processor.cpp
+++ b/tests/update/test-prefix-update-processor.cpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /*
- * Copyright (c) 2014-2021,  The University of Memphis,
+ * Copyright (c) 2014-2022,  The University of Memphis,
  *                           Regents of the University of California,
  *                           Arizona Board of Regents.
  *
@@ -40,7 +40,7 @@
 namespace nlsr {
 namespace test {
 
-class PrefixUpdateFixture : public nlsr::test::UnitTestTimeFixture
+class PrefixUpdateFixture : public UnitTestTimeFixture
 {
 public:
   PrefixUpdateFixture()