Support Robo 4

Author: Michaelvdwalle

composer.json

@@ -5,7 +5,7 @@
     "minimum-stability": "dev",
     "prefer-stable": true,
     "require": {
-        "consolidation/robo": "^3.0",
+        "consolidation/robo": "^3.0 || ^4.0",
         "phpseclib/phpseclib": "^3.0",
         "district09/backup-manager": "^4.0",
         "gordalina/cachetool": "^8",