Bring back oracle specific crap

activerecord/test/connections/oracle.rb

 ENV['ARCONN'] = 'oracle'
+
+# uses oracle_enhanced adapter in ENV['ORACLE_ENHANCED_PATH'] or from github.com/rsim/oracle-enhanced.git
+require 'active_record/connection_adapters/oracle_enhanced_adapter'
+
+# otherwise failed with silence_warnings method missing exception
+require 'active_support/core_ext/kernel/reporting'