Upgrading Instructions for Yii Framework v2
===========================================

!!!IMPORTANT!!!

The following upgrading instructions are cumulative. That is,
if you want to upgrade from version A to version C and there is
version B between A and C, you need to following the instructions
for both A and B.

Upgrade from Yii 2.0.0
----------------------

* MongoDB PHP extension min version raised up to 1.4.0. You should upgrade your environment in case you are
  using older version.

