Add signalr packages and example shared service that is injected into th...

...e OWIN host container and that is then subsequently injected into Nancy's and SignalR's containers.

There are 3 containers of interest - WebApplication's, SignalR's and Nancy's. Here we have an IExampleSharedService that is passed into all three. If you wanted to, you _could_ have a single over-arching application container (TinyIoC, AutoFac, Ninject etc) and replace the built-in ones of each framework. My personal preference is to keep them separate so I explicitly know what each component needs when I look at the WebStartup class.

Edit: Added an example test and made modifications such that the IDocumentStore is injected into the WebStartup instead of being activated in the nancy bootstrapper. This allows us to use the embeddable in-memory store for tests.