Cirrus-run

- API queries were updated to support changes in upstream GraphQL schema

- Project status changed from 'beta' to 'stable'. cirrus-run is in use for
almost two years with only minor changes, it's safe to say it's ready.
- Optionally retry flaky CI runs (detected by searching for text markers in CI
output)

- Gracefully handle GraphQL internal server errors wrapped into HTTP 200
response

- Added a longer one-time delay to wait out API server errors (see issue 7)
- Added a barebones test suite to (hopefully) eliminate regressions

Bugs were fixed, some features were added. Many thanks to [libvirt] team for
their feedback!

- New argument for managing CLI timeout
*(commit d5ad4bf)*
- Build logs can now be fetched from Cirrus CI and printed to stdout
*(issue 3)*
- Preempted CI instances do not cause cirrus-run to mistakenly report build
failure anymore
*(issue 4)*
- Automatic retries now happen also on API's internal server errors
*(pull request 6)*

[libvirt]: https://gitlab.com/libvirt/libvirt

v0.2.0 is the first cirrus-run release published to PyPI.
Feature set was not modified since the initial release.


Prior versions (2020-02-13..2020-02-18)

Earlier versions were not tagged and are not available from PyPI. See git
log for the list of changes.

First working version of cirrus-run was released on February 18th, 2020. This
[comment](https://github.com/cirruslabs/cirrus-ci-docs/issues/10#issuecomment-587532447)
marks the event.


[cirrus-run]: https://github.com/sio/cirrus-run