Unit testing project, along with almost half the unit tests I need
API looking good so far, repository pattern is a little weird when it comes to creating aggregates but I don't see any other way since we need to inject it with NServicebus container stuff
A big feature of Aggregate.NET is going to be the aggregate/entity router which will allow users to define entities on aggregates as well as the events entities need to care about.  The aggregate router will route messages that come to the aggregate to the appropriate entity.
Unfortunately this requires me to inject the class with an IEventRouter which in turn means the repository has to create the aggregate, not the user.

I **could** do some sort of static DI container like other people do, but we'll see how this works out.