Summary: Problem

We want to release the next versions of our Twitter OSS libraries 18.3.0
 - util
 - scrooge
 - finagle
 - twitter-server
 - finatra

Solution

Prepare libraries for their next releases.

JIRA Issues: CSL-6115

TBR=true

Differential Revision: https://phabricator.twitter.biz/D144231