Added MissingArgumentException that extends StandardException

src/Socialbox/Exceptions/Standard/MissingArgumentException.php

@@ -0,0 +1,18 @@
+<?php
+
+    namespace Socialbox\Exceptions\Standard;
+
+    use Socialbox\Enums\StandardError;
+
+    class MissingArgumentException extends StandardException
+    {
+        /**
+         * Thrown when a required parameter is missing
+         *
+         * @param string $parameterName
+         */
+        public function __construct(string $parameterName)
+        {
+            parent::__construct(sprintf('Missing required parameter: %s', $parameterName), StandardError::RPC_INVALID_ARGUMENTS);
+        }
+    }