Remove superclass definition from PostgreSQLAdapter patch, to use this gem together with ChronoModel

Author: vjt

Diff for: lib/activerecord-postgres-array/activerecord.rb

@@ -29,7 +29,7 @@ def arel_attributes_values(include_primary_key = true, include_readonly_attribut
   end
 
   module ConnectionAdapters
-    class PostgreSQLAdapter < AbstractAdapter
+    class PostgreSQLAdapter
       POSTGRES_ARRAY_TYPES = %w( string text integer float decimal datetime timestamp time date binary boolean )
 
       def native_database_types_with_array(*args)