prepare release

CHANGELOG.md

@@ -9,6 +9,8 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 
 ## [Unreleased]
 
+## [2.1.0] - 2019-12-27
+
 ### Changed
 
 - `Http\Client\Exception\NetworkException` no longer extends `Http\Client\Exception\RequestException`,

composer.json

@@ -35,7 +35,7 @@
     },
     "extra": {
         "branch-alias": {
-            "dev-master": "2.0.x-dev"
+            "dev-master": "2.x-dev"
         }
     }
 }