Problem

We want to release the next versions our of Twitter OSS libraries:
  - util -> 6.39.0
  - ostrich -> 9.23.0
  - scrooge -> 4.12.0
  - finagle -> 6.40.0
  - twitter-server -> 1.25.0
  - finatra -> 2.6.0

Solution

Prepare libraries for their next releases.

RB_ID=892743
TBR=true