build: Removal of unused php-http/message-factory dependency (#6)

Author: N-M

composer.json

@@ -21,7 +21,6 @@
     "php-http/httplug": "^1.1 || ^2.0",
     "php-http/logger-plugin": "^1.3",
     "php-http/message": "^1.5",
-    "php-http/message-factory": "^1.1",
     "psr/http-factory": "^1.0",
     "psr/http-factory-implementation": "^1.0",
     "psr/log": "^1.0 || ^2.0 || ^3.0",