0.16.4

This is a stable release of ARA, 0.16.4.

***
WARNING: Please note that the next major version of ARA, 1.0, is
         currently in beta and is not backwards compatible with ARA 0.x.
         In order to avoid upgrading unexpectedly when 1.0 is released,
         we recommend pinning ara to <1.0.0 in your scripts and requirements.
***

Changelog since 0.16.3:
- Fixed a regression when saving tasks with Ansible 2.8 [1]

[1]: https://github.com/ansible-community/ara/issues/46