Add release notes for 0.5.13
# Release Notes
+## Changes in Splinter 0.5.13
+
+### Highlights
+
+* The initial experimental implementation of Challenge Authorization has been
+ added. See [Challenge
+ Authorization](https://www.splinter.dev/community/planning/challenge_authorization.html)
+ for more information.
+
+### libsplinter
+
+* Implement Challenge Authorization. Challenge Authorization is behind an
+ experimental feature `challenge-authorization`.
+
+* Update the Admin Service to support Challenge Authorization. This is behind
+ the experimental feature `challenge-authorization`.
+
+* Update PeerManager and ConnectionManger to pass the expected authorization of
+ the peer, as well as the authorization the local node must use for
+ authorization. This is required to properly connect to a peer based on the
+ requirements of a circuit. This is behind the experimental feature
+ `challenge-authorization`.
+
+* Add experimental NodeIdStore with diesel implementation. This store adds an
+ alternative place to store the node id, which is saved on the first run of
+ splinter.
+
+### splinterd
+
+* Update the creation of the AuthorizationManager to support Challenge
+ Authorization.
+
## Changes in Splinter 0.5.12
### Highlights
