Prepare for release v2.4.0

Author: dirkgr

CHANGELOG.md

@@ -6,7 +6,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
 
-## Unreleased
+## [v2.4.0](https://github.com/allenai/allennlp-models/releases/tag/v2.4.0) - 2021-04-22
 
 ### Added
 

allennlp_models/version.py

@@ -1,7 +1,7 @@
 import os
 
 _MAJOR = "2"
-_MINOR = "3"
+_MINOR = "4"
 _PATCH = "0"
 # This is mainly for nightly builds which have the suffix ".dev$DATE". See
 # https://semver.org/#is-v123-a-semantic-version for the semantics.