Remove example dependencies

Author: Jonathon Hill

composer.json

@@ -36,10 +36,8 @@
         "react/stream": "^1.4"
     },
     "require-dev": {
-        "clue/http-proxy-react": "^1.8",
-        "clue/reactphp-ssh-proxy": "^1.4",
-        "clue/socks-react": "^1.4",
         "phpunit/phpunit": "^9.6 || ^5.7 || ^4.8.36",
+        "psr/http-message": "^2.0",
         "react/async": "^4.2 || ^3 || ^2",
         "react/promise-stream": "^1.4",
         "react/promise-timer": "^1.11"