chore(release): Prepare development of next version

Author: dborsatto

CHANGELOG.md

@@ -3,6 +3,8 @@
 All notable changes to this project will be documented in this file.
 This project adheres to [Semantic Versioning](http://semver.org/).
 
+## [Unreleased](https://github.com/contentful/contentful-core.php/compare/2.0.0...HEAD)
+
 ## [2.0.0](https://github.com/contentful/contentful-core.php/tree/2.0.0) (2018-10-30)
 
 **ATTENTION**: This release contains breaking changes. Please take extra care when updating to this version. See [the upgrade guide](UPGRADE-2.0.md) for more.

composer.json

@@ -37,7 +37,7 @@
     },
     "extra": {
         "branch-alias": {
-            "dev-master": "2.0.0-dev"
+            "dev-master": "2.1.0-dev"
         }
     }
 }