update play-json 2.3.1 & akka-actor 2.3.4. Bump v3.1.5

bump v3.1.4. Update deps

bump v3.1.3. Update play-json

update couchbase-client 1.4.1

+ Change nothing in code but update play-json (optional dependency) t…

…o 2.3.0-RC1 & akka-actor 2.3.2

+ cross compile for scala 2.11 & scala 2.10
+ Also update sbt 0.13.5-RC1
+ Bump v3.1.0

update specs2 2.3.11

v3.0.0. @see README.md

use sbt-sonatype plugin & bump v2.1.4