Fixes: #74
note: This relies on the fix for dapr/dapr#574 which has been merged.
This change introduces a middleware that can upwrap a *structured* cloud
event. This is the format used by dapr by default now for pub/sub
messaging. Adding the middleware makes it transparent to the developer
whether the data can from a cloud event or was a basic RPC call.
We're adding the middleware for this first since it's the most general
approach. It has a drawback compared with other approaches, performance.
Users could alternatively use the SDK from CloudEvents to read their
data without the middleware.
We might also want to add an MVC formatter in the future, which could do
the unwrapping and deserialization to a user-type in a single operation.
Dmitry Shmulevich
Ryan Nowak