Version 1.2.0

• Enh #230: Improve column type #230 (@Tigrov)
• Enh #243: Move methods from Command to AbstractPdoCommand class (@Tigrov)
• Bug #233: Refactor DMLQueryBuilder, related with yiisoft/db#746 (@Tigrov)
• Bug #240: Remove RECURSIVE expression from CTE queries (@Tigrov)
• Bug #242: Fix AbstractDMLQueryBuilder::batchInsert() for values as associative arrays,
  related with yiisoft/db#769 (@Tigrov)