update install tasks

Update install tasks with defaults using 1.9 hash syntax
(cherry picked from commit fa74299)

lib/neo4j/tasks/neo4j_server.rake

@@ -92,6 +92,7 @@ namespace :neo4j do
 
   desc 'Install Neo4j with auth disabled in v2.2+, example neo4j:install[community-latest,development]'
   task :install, :edition, :environment do |_, args|
+    args.with_default_arguments(edition: 'community-latest', environment: 'development')
     edition = get_edition(args)
     environment = get_environment(args)
     puts "Installing Neo4j-#{edition} environment: #{environment}"