Re-added updated slack library

composer.json

@@ -42,7 +42,7 @@
     "league/csv": "^9.5",
     "league/flysystem-aws-s3-v3": "^1.0",
     "league/flysystem-cached-adapter": "^1.0",
-    "maknz/slack": "^1.7",
+    "alek13/slack": "^1.7",
     "neitanod/forceutf8": "^2.0",
     "nesbot/carbon": "^2.32",
     "onelogin/php-saml": "^3.4",