Bump version to 0.4.0

CHANGELOG.md

@@ -1,4 +1,4 @@
-# v0.4.0 (unreleased)
+# v0.4.0 (2022-09-17)
 
 Target signald version: [v0.21.1](https://gitlab.com/signald/signald/-/releases/0.21.1)
 

mautrix_signal/__init__.py

@@ -1,2 +1,2 @@
-__version__ = "0.3.0"
+__version__ = "0.4.0"
 __author__ = "Tulir Asokan <tulir@maunium.net>"