def change_column(column_name, definition)
      attributes = column_attributes(column_name, definition)
      migration.change_column(*attributes)
    end
def change_column(column_name, definition)
      attributes = column_attributes(column_name, definition)
      migration.change_column(*attributes)
    end
Change the column to use the provided definition, through ActiveRecord

 @param column_name [String, Symbol]
 @param definition [String, Symbol]