twitter-oss: Prepare OSS libraries for release 18.9.1

Problem

We want to release the next versions of our Twitter OSS libraries 18.9.1
 - util
 - scrooge
 - finagle
 - twitter-server
 - finatra

Solution

Prepare libraries for their next releases.

Differential Revision: https://phabricator.twitter.biz/D220746

CHANGELOG.rst

@@ -7,6 +7,9 @@ Note that ``PHAB_ID=#`` and ``RB_ID=#`` correspond to associated messages in com
 Unreleased
 ----------
 
+18.9.1
+-------
+
 * scrooge: Finally remove `maven.twttr.com` as a dependency or plugin repository. With 
   the update to a more recent libthrift dependency, this should no longer be necessary. 
   ``PHAB_ID=D219665``

README.md

@@ -1,6 +1,6 @@
 # Scrooge
 
-[![Build status](https://travis-ci.org/twitter/scrooge.svg?branch=develop)](https://travis-ci.org/twitter/scrooge)
+[![Build status](https://travis-ci.org/twitter/scrooge.svg?branch=master)](https://travis-ci.org/twitter/scrooge)
 [![Codecov](https://codecov.io/gh/twitter/scrooge/branch/develop/graph/badge.svg)](https://codecov.io/gh/twitter/scrooge)
 [![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

@@ -5,7 +5,7 @@ import scoverage.ScoverageKeys
 // 'git checkout develop; sbt publishLocal' to publish SNAPSHOT versions of these projects.
 
 // All Twitter library releases are date versioned as YY.MM.patch
-val releaseVersion = "18.10.0-SNAPSHOT"
+val releaseVersion = "18.9.1"
 
 val libthriftVersion = "0.10.0"
 

demos/scrooge-maven-demo/pom.xml

@@ -33,27 +33,27 @@
     <dependency>
       <groupId>com.twitter</groupId>
       <artifactId>util-core_2.12</artifactId>
-      <version>18.10.0-SNAPSHOT</version>
+      <version>18.9.1</version>
     </dependency>
     <dependency>
       <groupId>com.twitter</groupId>
       <artifactId>util-codec_2.12</artifactId>
-      <version>18.10.0-SNAPSHOT</version>
+      <version>18.9.1</version>
     </dependency>
     <dependency>
       <groupId>com.twitter</groupId>
       <artifactId>finagle-core_2.12</artifactId>
-      <version>18.10.0-SNAPSHOT</version>
+      <version>18.9.1</version>
     </dependency>
     <dependency>
       <groupId>com.twitter</groupId>
       <artifactId>finagle-thrift_2.12</artifactId>
-      <version>18.10.0-SNAPSHOT</version>
+      <version>18.9.1</version>
     </dependency>
     <dependency>
       <groupId>com.twitter</groupId>
       <artifactId>scrooge-core_2.12</artifactId>
-      <version>18.10.0-SNAPSHOT</version>
+      <version>18.9.1</version>
     </dependency>
     <dependency>
       <groupId>junit</groupId>
@@ -132,7 +132,7 @@
       <plugin>
         <groupId>com.twitter</groupId>
         <artifactId>scrooge-maven-plugin</artifactId>
-        <version>18.10.0-SNAPSHOT</version>
+        <version>18.9.1</version>
         <configuration>
           <thriftNamespaceMappings>
             <thriftNamespaceMapping>

scrooge-maven-plugin/pom.xml

@@ -5,7 +5,7 @@
   <artifactId>scrooge-maven-plugin</artifactId>
   <packaging>maven-plugin</packaging>
   <name>scrooge-maven-plugin</name>
-  <version>18.10.0-SNAPSHOT</version>
+  <version>18.9.1</version>
   <prerequisites>
     <maven>3.0.4</maven>
   </prerequisites>
@@ -247,7 +247,7 @@
     <dependency>
       <groupId>com.twitter</groupId>
       <artifactId>scrooge-generator_2.10</artifactId>
-      <version>18.10.0-SNAPSHOT</version>
+      <version>18.9.1</version>
     </dependency>
     <!-- Test Dependencies-->
     <dependency>