Remove Akka.DI Examples

[Aaronontheweb]

Now that #942 has been completed, it's no longer necessary to keep examples of how to work with each DI container inside the Akka.NET project itself.

We'll be posting examples of how to call each DI container on the http://getakka.net/ website.

So in order to cut the build time and size of the solution down, we should remove all of the DI samples.

[Aaronontheweb]

closed by #1180