This is a breaking change.
The `testing` feature no longer exists. Testing structures can now be
accessed without any features enabled.
Prior to this change, Rocket would panic when draining from a network
stream failed. With this change, Rocket force closes the stream on any
error.
This change also ensures that the `Fairings` launch output only prints
if at least one fairing has been attached.
This commit includes the following additions:
* A `session` example was added.
* `Config::take_session_key` was removed.
* If a `session_key` is not supplied, one is automatically generated.
* The `Session` type implements signed, encrypted sessions.
* A `Session` can be retrieved via its request guard.
Sergio Benitez