[STORE] Remove the reference to the persistence branch in the Rails template

Author: karmi

elasticsearch-persistence/examples/music/template.rb

@@ -132,7 +132,7 @@
 gem "simple_form"
 
 gem 'elasticsearch', git: 'git://github.com/elasticsearch/elasticsearch-ruby.git'
-gem 'elasticsearch-persistence', git: 'git://github.com/elasticsearch/elasticsearch-rails.git', branch: 'persistence-model', require: 'elasticsearch/persistence/model'
+gem 'elasticsearch-persistence', git: 'git://github.com/elasticsearch/elasticsearch-rails.git', require: 'elasticsearch/persistence/model'
 gem 'elasticsearch-rails', git: 'git://github.com/elasticsearch/elasticsearch-rails.git'
 
 git add:    "Gemfile*"