End to end latency increased due to featch max wait time increased in Sarama

[ppatierno]

While testing RC2, we found that the end to end latency on the canary was increased.
After some investigation (thanks to @k-wall) it turned out that the following change in Sarama is the root cause: IBM/sarama#2227
It highlights that there could be a potential bug elsewhere in Sarama which has to be addressed.
Meanwhile, the canary can be updated by setting that consumer max time to the same 250 ms (as before in Sarama).

[ppatierno]

Closed by #183