meta: Updated changelog

Author: mitsuhiko

CHANGELOG.md

@@ -1,5 +1,16 @@
 # Changelog
 
+# 0.9.0
+
+* Removed `drain_events`.  Events are now drained by calling `Client::close` or on the
+  transport on `Transport::shutdown`.
+* Removed `Hub::add_event_processor`.  This was replaced by `Scope::add_event_processor`
+  which is easier to use (only returns factory function)/
+* Added various new client configuration values.
+* Unified option handling
+
+This is likely to be the final API before 1.0
+
 # 0.3.1
 
 * Remove null byte terminator from device model context (#33)