README.md in event_sourcery-postgres-0.5.0 vs README.md in event_sourcery-postgres-0.6.0

@@ -20,10 +20,9 @@
 
 ```ruby
 EventSourcery::Postgres.configure do |config|
   config.event_store_database = Sequel.connect(...)
   config.projections_database = Sequel.connect(...)
-  config.use_optimistic_concurrency = true
   config.write_events_function_name = 'writeEvents'
   config.events_table_name = :events
   config.aggregates_table_name = :aggregates
   config.callback_interval_if_no_new_events = 60
 end