Follow PSR-2 code style

[CasperLaiTW]

Should *.stub file or generator creating file be follow psr-2?

Ex:
migration.stub

Convert 1 tab to 4 space ?

[codingquark]

Also, for constructor, we cannot omit accessibility declaration according to PSR2. So, current code function __construct should be public function __construct

[mitulgolakiya]

fixed.