Add release notes for 0.5.6
# Release Notes
+## Changes in Splinter 0.5.6
+
+### Highlights
+
+* The Splinter daemon now has its own sets of private/public keys that will be
+ used to support Challenge Authorization.
+
+### libsplinter
+
+* Replace MigrationError with InternalError. This has the effect of properly
+ displaying the underlying error that may occur when accessing the database.
+
+* Add REST endpoint to the OAuthResourceProvider, oauth/users behind the
+ `oauth-user-list` feature, which lists OAuth users. This makes it easy for
+ administrators to get users' Biome IDs so they can be used in RBAC
+ authorization.
+
+* Stabilized the `proposal-removal` feature. This enables removing a circuit
+ proposal for the requesting node.
+
+### splinter CLI
+
+* Update `splinter keygen --system` to check the environment variables
+ `SPLINTER_HOME` and `SPLINTER_CONFIG_DIR` for where to put the generated keys.
+ Also updates the default key name to be `splinterd`.
+
+### splinterd
+
+* Add public/private keys to the Splinter daemon. If the experimental feature
+ `challenge-authorization` is enabled, the daemon will check the configured
+ "config" directory and load every key that is in the key directory. These keys
+ will be used in challenge authorization.
+
## Changes in Splinter 0.5.5
### Highlights
