Updated dependencies.

Author: JanSlabon

composer.json

@@ -11,17 +11,16 @@
         }
     ],
     "require": {
-        "php": ">=7.1",
+        "php": ">=7.3 <=8.5.99999",
         "ext-json": "*",
         "psr/http-client": "^1.0",
         "psr/http-factory": "^1.0",
-        "setasign/setapdf-signer": "^2.40"
+        "setasign/setapdf-signer": "^2.47"
     },
     "require-dev": {
-        "guzzlehttp/guzzle": "^6.5",
+        "guzzlehttp/guzzle": "^7.10.0",
         "http-interop/http-factory-guzzle": "^1.0",
-        "mjelamanov/psr18-guzzle": "^1.3",
-        "phpseclib/phpseclib": "^2.0",
+        "phpseclib/phpseclib": "^3.0",
         "league/oauth2-client": "^2.6"
     },
     "autoload": {