the new ClusterAdmin's CreateTopic has no timeout setting

[dt665m]

Versions

Please specify real version numbers or git SHAs, not just "Latest" since that changes fairly regularly.
Sarama Version: 46cf3e2
Kafka Version:
Go Version:

Problem Description

ClusterAdmin's CreateTopic does not populate a sensible timeout or require a timeout in the function signature for the CreateTopicsRequest struct, causing a call to this function to always return a timeout error even on success.

I was going to do a quick PR but don't have time to do the dependencies and I'm not sure if people want control of the timeout or a sensible default is sufficient since the ClusterAdmin stuff is new.

[dt665m]

closed, duplicate of #1120