v4.1.0

This release includes many performance fixes and new features. The most notable:

• Huge stylist cleanup/refactoring by Brian on the entire gem by Brian armed with Rubocop. See http://neo4jrb.io/blog/2014/12/29/stay-out-of-trouble.html.
• Every node create, update, and destroy is now wrapped in a transaction. See http://neo4jrb.io/blog/2015/01/06/transactions_everywhere.html.
• New dependent options for associations: :delete, :destroy, :delete_orphans, :destroy_orphans. See http://neo4jrb.io/blog/2015/01/07/association_dependent_options.html.
• New unique: true option for associations, creates_unique_rel class method for ActiveRel. Both of these will result in relationship creation Cypher using "CREATE UNIQUE" instead of "CREATE".
• Fixed an n+1 query issue during node creation and update.
• Dieter simplified some code related to frozen attributes. See #655.
  We now have a new website online at http://neo4jrb.io! Keep an eye on it for news and blogs related to this and other projects.