Twitter-oss: Prepare OSS libraries for release 19.3.0

Problem

We want to release the next versions of our Twitter OSS libraries 19.3.0
 - util
 - scrooge
 - finagle
 - twitter-server
 - finatra

Solution

Prepare libraries for their next releases.

Differential Revision: https://phabricator.twitter.biz/D285479

CHANGELOG.rst

@@ -7,17 +7,20 @@ Note that ``PHAB_ID=#`` and ``RB_ID=#`` correspond to associated messages in com
 Unreleased
 ----------
 
+19.3.0
+------
+
 * Change the /admin/histograms?h=...-style endpoints to return data in the same style as
   /admin/histograms.json. This should make it easier to use tools to parse data from either
   endpoint. ``PHAB_ID=D279779``
 
 19.2.0
--------
+------
 
 No Changes
 
 19.1.0
--------
+------
 
 * Propagate the admin server's shutdown to the handlers that are registered with the admin server.
   ``PHAB_ID=D254656``

README.md

@@ -1,6 +1,6 @@
 # TwitterServer
 
-[![Build status](https://travis-ci.org/twitter/twitter-server.svg?branch=develop)](https://travis-ci.org/twitter/twitter-server)
+[![Build status](https://travis-ci.org/twitter/twitter-server.svg?branch=master)](https://travis-ci.org/twitter/twitter-server)
 [![Codecov](https://codecov.io/gh/twitter/twitter-server/branch/develop/graph/badge.svg)](https://codecov.io/gh/twitter/twitter-server)
 [![Project status](https://img.shields.io/badge/status-active-brightgreen.svg)](#status)
 [![Gitter](https://badges.gitter.im/twitter/finagle.svg)](https://gitter.im/twitter/finagle?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge)

build.sbt

@@ -1,7 +1,7 @@
 import scoverage.ScoverageKeys
 
 // All Twitter library releases are date versioned as YY.MM.patch
-val releaseVersion = "19.3.0-SNAPSHOT"
+val releaseVersion = "19.3.0"
 
 val jacksonVersion = "2.9.6"
 val jacksonLibs = Seq(