Bump master version to 2.2-develop
#include "astcenccli_internal.h"
const char *astcenc_copyright_string =
-R"(ASTC codec v2.1, %u-bit %s%s
+R"(ASTC codec v2.2-develop, %u-bit %s%s
Copyright 2011-2020 Arm Limited, all rights reserved
)";
