Add fixer for form type getName method.

[kristijanhusak]

From https://github.com/symfony/symfony/blob/2.8/UPGRADE-2.8.md

As a further consequence, the method FormTypeInterface::getName() was deprecated and will be removed in Symfony 3.0. You should remove this method from your form types.

If you want to customize the block prefix of a type in Twig, you should now implement FormTypeInterface::getBlockPrefix() instead:

Before:

   class UserProfileType extends AbstractType
   {
       public function getName()
       {
           return 'profile';
       }
   }

After:

   class UserProfileType extends AbstractType
   {
       public function getBlockPrefix()
       {
           return 'profile';
       }
   }

[umpirsky]

Thanks @kristijanhusak! :+1: I was planning to do this one for a while, lack of time as always. :)

I will review your PR later today.

[kristijanhusak]

No problem :wink:

I really missed this one today when i was updating a project.

This is really helpful package, it saved me a lot of time and search/replace actions, keep up the good work!

[umpirsky]

@kristijanhusak It also says "If you define your form types in the Dependency Injection configuration, you should further remove the "alias" attribute.". Does it works if you leave it?

[kristijanhusak]

It works, it just ignores the alias.

[umpirsky]

@kristijanhusak Cool. Then we can merge this after you fix my last remark and release new version. :+1:

[umpirsky]

Perfect, thanks @kristijanhusak! :+1: