New features:
* After connecting an org with ``cci org connect``, the browser now shows the message
"Congratulations! Your authentication succeeded." instead of "OK"
* External GitHub sources can now specify ``release: latest``, ``release: latest_beta``,
or ``release: previous`` instead of a commit, branch, or tag.
* The ``execute_anon`` task has been revised to detect when a gack occurred during execution.
Issues closed:
* When importing a scratch org from sfdx using ``cci org import``, the org's ``days``
is now set correctly from the org's actual expiration date. (1101)
* The package API version from ``cumulusci.yml`` is now validated to make sure
it's in the "XX.0" format expected by the API. (1134)
* Fixed an error deploying new setting objects using the ``org_settings`` task in Winter '20.
* Fixed a bug in processing preflight check tasks for MetaDeploy.
* Fixed path handling in the ``update_admin_profile`` task when run in a cross-project flow.