Merge pull request #303 from fulinlin924/master

fix split grouped nodes
anormdb: fix span merging

Annotations and binary annotations were not joined with spans
predicated on span names. This caused for duplicate annotations to
show up in the UI.

Author: @franklinhu
Fixes #308
URL: https://github.com/twitter/zipkin/pull/308
switch to the official scrooge-sbt plugin

Author: @sprsquish
Fixes #312
URL: https://github.com/twitter/zipkin/pull/312
Merge branch 'twitter.master'