* Remove Ubuntu 16.04 (Xenial Xerus) from CI.
* Removing PyOpenSSL backend from everywhere but openssl_pkcs12.
* Remove PyOpenSSL support from module_utils that's not needed for openssl_pkcs12.
* Add changelog fragment.
* Install PyOpenSSL and cryptography from PyPi if target Python != system Python.
* Work around some CentOS6, 7, Ubuntu 16.04 problems. Improve jinja2 compatibility handling.
* Skip tasks that require properties that aren't always there.
* Only install OpenSSL when not present.
* Improve output.
* Improve get_certificate integration test graceful failing.
* Fix tests.
* Fix assert.
* OpenSSL peculiarities.
* Fix condition.