What happened (please include outputs or screenshots):

When the KubernetesPodOperator in airflow runs it outputs this log without breaking.
{kube_config.py:520} ERROR - 'NoneType' object has no attribute 'groups'

I have traced it back to the parse_rfc3339 function that is not guarding against search returning None.
https://github.com/kubernetes-client/python/blob/master/kubernetes/base/config/kube_config.py#L515-L520
https://github.com/kubernetes-client/python/blob/master/kubernetes/base/config/dateutil.py#L50-L77

What you expected to happen:
parse_rfc3339 should guard against this better and/or have a better error message that shows the string the regex is running on.