Fix missing realloc function in SI

The realloc payload function was missing in the SI port.

This change also adds the ability to build and run SI95
test applications in the test_app directory. NNG tests
are still run by default (this will be changed eventually).

Signed-off-by: E. Scott Daniels <daniels@research.att.com>
Change-Id: Ie8a453a009767afcf23eac610dc5f976b880d0aa
diff --git a/CHANGES b/CHANGES
index 3ae419a..976169f 100644
--- a/CHANGES
+++ b/CHANGES
@@ -2,6 +2,9 @@
 API and build change  and fix summaries. Doc correctsions
 and/or changes are not mentioned here; see the commit messages.
 
+2020 January 21; verison 3.0.2
+	Fix bug in SI95 (missing reallocate payload function).
+
 2020 January 20; verison 3.0.1
 	Enable support for dynamic route table updates via RMR session.