twitter-oss: Prepare OSS libraries for release

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

CHANGES

@@ -6,6 +6,8 @@ Note that ``RB_ID=#`` correspond to associated messages in commits.
 
 Next Version
 
+6.37.0  2016-09-07
+
 New Features:
 
   * util-app: Introduce `c.t.app.Flag.letClear` allowing flags to be unset.

README.md

@@ -37,7 +37,7 @@ for more details about how to contribute.
 An example SBT dependency string for the `util-collection` tools would look like this:
 
 ```scala
-val collUtils = "com.twitter" %% "util-collection" % "6.36.0"
+val collUtils = "com.twitter" %% "util-collection" % "6.37.0"
 ```
 
 # Units

project/Build.scala

@@ -10,7 +10,7 @@ object Util extends Build {
   val branch = Process("git" :: "rev-parse" :: "--abbrev-ref" :: "HEAD" :: Nil).!!.trim
   val suffix = if (branch == "master") "" else "-SNAPSHOT"
 
-  val libVersion = "6.36.0" + suffix
+  val libVersion = "6.37.0" + suffix
   val zkVersion = "3.5.0-alpha"
   val zkClientVersion = "0.0.79"
   val zkGroupVersion = "0.0.90"