Updated changelog after merge of wolfSSL#97. Tag v1.7.1.

Updated README.md with changelog

Merge pull request wolfSSL#76 from wolfSSL/prepare-release-1.6

Prepare release 1.6

Fixed allocation size in RSA4096

wolfBoot version 1.4

Added missing file for stm32wb55 hal configuration

Merge pull request wolfSSL#18 from wolfSSL/stm32wb55

Added support for STM32WB

Updated README, v1.1 release notes

Updated wolfSSL submodule