Update changelog

Author: Susurrus

CHANGELOG.asciidoc

@@ -5,6 +5,10 @@ All notable changes to this project will be documented in this file.
 The format is based on http://keepachangelog.com/[Keep a Changelog]
 and this project adheres to http://semver.org/[Semantic Versioning].
 
+=== Unreleased
+==== Changed
+* USB device information is now returned in calls to `available_ports()`
+
 === [1.0.1] - 2017-02-20
 ==== Fixed
 * `read()` now properly blocks for at least one character