move roles into host

@andreasohlund the reason as I stated is because in the Azure host we currently support:
```c#
public class EndpointConfig : IConfigureThisEndpoint, AsA_Worker, UsingTransport<AzureStorageQueue>, UsingPersistence<AzureStorage>
```
As a user I would expect the same for regular host, eg
```c#
public class EndpointConfig : IConfigureThisEndpoint, AsA_Publisher, UsingTransport<Msmq>, UsingPersistence<RavenDB>
```