Prepare for release v2.7.0

Author: epwalsh

CHANGELOG.md

@@ -7,6 +7,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## Unreleased
 
+
+## [v2.7.0](https://github.com/allenai/allennlp/releases/tag/v2.7.0) - 2021-09-01
+
 ### Added
 
 - Added support to evaluate mutiple datasets and produce corresponding output files in the `evaluate` command.

CITATION.cff

@@ -42,6 +42,6 @@ license: "Apache-2.0"
 message: "If you use this software, please cite it using this metadata."
 repository-code: "https://github.com/allenai/allennlp"
 title: "AllenNLP: A Deep Semantic Natural Language Processing Platform"
-version: "2.6.0"
+version: "2.7.0"
 doi: "10.18653/v1/W18-2501"
 ...