Bump gotify/server version (2.3.0 => 2.4.0) (#270)

* Update .ci\docker-compose.yml
* Update .devcontainer\docker-compose.yml
* Update README.md

Author: VerifiedJoseph

.ci/docker-compose.yml

@@ -3,7 +3,7 @@ version: "3"
 services:
   gotify:
     container_name: ci_gotify
-    image: gotify/server:2.3.0
+    image: gotify/server:2.4.0
     ports:
       - "127.0.0.1:8080:80"
     environment:

.devcontainer/docker-compose.yml

@@ -13,7 +13,7 @@ services:
 
   gotify:
     container_name: gotify
-    image: gotify/server:2.3.0
+    image: gotify/server:2.4.0
     ports:
       - "8080:80"
     environment:

README.md

@@ -5,7 +5,7 @@
 
 PHP library for interacting with a [Gotify](https://github.com/gotify/server) server using the [Gotify REST-API](https://gotify.net/api-docs).
 
-Supports Gotify server version 2.3.0.
+Supports Gotify server version 2.4.0.
 
 ## Install