Update changelog

CHANGELOG.md

@@ -1,6 +1,7 @@
 * 1.0.0-alpha3
 
   * Schema: Added 'require-dev' for development-time requirements (tests, etc), install with --dev
+  * Schema: Added author.role to list the author's role in the project
   * Schema: Removed 'recommend'
   * Schema: 'suggest' is now informational and can use any description for a package, not only a constraint
   * Break: vendor/.composer/autoload.php has been moved to vendor/autoload.php, other files are now in vendor/composer/
@@ -8,6 +9,8 @@
   * Added removal of packages that are not needed anymore
   * Added include_path support for legacy projects that are full of require_once statements
   * Added installation notifications API to allow better statistics on Composer repositories
+  * Added support for proxies that require authentication
+  * Added support for private github repositories over https
   * Added autoloading support for root packages that use target-dir
   * Added awareness of the root package presence and support for it's provide/replace/conflict keys
   * Added IOInterface::isDecorated to test for colored output support