Sheperd wanted for new contributor

[Bechstein, Felix]

Hi,
I'd like to work on MESOS-3307 "Configurable size of completed task / framework 
history" [1]. Can someone be the sheperd?
I created accounts for jira and review with username "flx".
I'd like to discuss my changes. There is already PR on github [2].
Thanks.
Regards,
Felix
[1]: https://issues.apache.org/jira/browse/MESOS-3307
[2]: https://github.com/apache/mesos/pull/82