Scan an assembly in order to create a DataContractContentSerializer

Resolves #100.
Oh :$ I see... Thank you for clarifying this.

Unless I'm missing something, `Scan` returns an *IContentSerializer* which is actually a `DataContractContentSerializer`.

How can we verify that `Scan` *returns correct result*?
 * Verify that it's actually a `DataContractContentSerializer`.
 * Verify that it's created with the expected `ITypeResolver`.