Problem

We want to release the next versions our of Twitter OSS libraries:
  - util -> 6.37.0
  - ostrich -> 9.21
  - scrooge -> 4.10.0
  - finagle -> 6.38.0
  - twitter-server -> 1.23
  - finatra -> 2.4.0

Solution

Prepare libraries for their next releases.

RB_ID=868959