0.15.0.0rc1

This is a release candidate for the newest stable release of ARA, 0.15.0.

***
WARNING: Please note that the next major version of ARA, 1.0, will contain
         backwards incompatible changes due to significant refactor work
         involving core back end code as well as the SQL database schema.
***

Changelog:

- ARA: Ansible Run Analysis has been "rebranded" to ARA Records Ansible
  (Another Recursive Acronym)
- Significant improvements to memory usage and performance when running ARA as
  a WSGI application with 'ara-wsgi' or 'ara-wsgi-sqlite'.
- Resolved an issue where the 'ara-wsgi-sqlite' middleware could serve a
  cached report instead of the requested one
- Added support for configuring the 'SQLALCHEMY_POOL_SIZE',
  'SQLALCHEMY_POOL_TIMEOUT' and 'SQLALCHEMY_POOL_RECYCLE' parameters.
  See the configuration documentation [1] for more details.
- Logging was fixed and improved to provide better insight when in DEBUG level.
- Vastly improved the default logging configuration.
  ARA will create a default logging configuration file in '~/.ara/logging.yml'
  that you can customize, if need be. Deleting this file will make ARA create
  a new one with updated defaults.
- Added python modules to help configure Ansible to use ARA, for example,
  'python -m ara.setup.callback_plugins' will print the path to ARA's callback
  plugins.
  You can find more examples in the configuration documentation. [1]
- Implemented a workaround for fixing a race condition where an
  'ansible-playbook' command may be interrupted after the playbook was recorded
  in the database but before playbook file was saved.
- Flask 0.12.3 was blacklisted from ARA's requirements [2], this was a broken
  release.
- The ARA CLI can now be called with "python -m ara" if you need to specify a
  specific python interpreter, for example.
- Updated and improved integration tests across different operating systems,
  python2 and python3 with different versions of Ansible. The full test matrix
  is available in the README. [3].

[1]: https://ara.readthedocs.io/en/stable/configuration.html
[2]: https://github.com/openstack/ara/commit/87272840bfc8b4c5db10593e47884e33a0f4af40
[3]: https://github.com/openstack/ara#contributing-testing-issues-and-bugs
This tag has no release notes.