IVGCVSW-4485 Remove Boost assert

 * Change boost assert to armnn assert
 * Change include file to armnn assert
 * Fix ARMNN_ASSERT_MSG issue with multiple conditions
 * Change BOOST_ASSERT to BOOST_TEST where appropriate
 * Remove unused include statements

Signed-off-by: Narumol Prangnawarat <narumol.prangnawarat@arm.com>
Change-Id: I5d0fa3a37b7c1c921216de68f0073aa34702c9ff
diff --git a/tests/MnistDatabase.cpp b/tests/MnistDatabase.cpp
index bd5029f..c1c5f63 100644
--- a/tests/MnistDatabase.cpp
+++ b/tests/MnistDatabase.cpp
@@ -7,7 +7,7 @@
 #include <armnn/Logging.hpp>
 
 #include <boost/numeric/conversion/cast.hpp>
-#include <boost/assert.hpp>
+
 #include <fstream>
 #include <vector>