change back the readme instruction for creating new project.

apps/advanced/README.md

@@ -70,7 +70,7 @@ at [getcomposer.org](http://getcomposer.org/doc/00-intro.md#installation-nix).
 You can then install the application using the following command:
 
 ~~~
-php composer.phar create-project --stability=alpha yiisoft/yii2-app-advanced advanced
+php composer.phar create-project --stability=dev yiisoft/yii2-app-advanced advanced
 ~~~
 
 

apps/basic/README.md

@@ -52,7 +52,7 @@ at [getcomposer.org](http://getcomposer.org/doc/00-intro.md#installation-nix).
 You can then install this application template using the following command:
 
 ~~~
-php composer.phar create-project --stability=alpha yiisoft/yii2-app-basic basic
+php composer.phar create-project --stability=dev yiisoft/yii2-app-basic basic
 ~~~
 
 Now you should be able to access the application through the following URL, assuming `basic` is the directory