1.6.0
* Adding OpenSSL Engine support. * Updating submodule * Modifying DevOps invalid name. * Updating submodule. * Removing gcc44, 46 merge issue. * Updating valgrind suppressions. * Adding suppressions for new Openssl/engine tests. * Adding documentation, addressing PR feedback. * Addressing feedback. Fixing docker image name. * Updating docker image. * Removing token removal. * Moving to self-hosted OSX agent. * Increasing version to 1.6.0 * Updating submodules.