Merge pull request #18 from srdante/patch-1

Fix "Return value of Tighten\SolanaPhpSdk\Program::__call() must be of the type array or null, int returned"

src/Program.php

@@ -14,7 +14,7 @@ public function __construct(SolanaRpcClient $client)
         $this->client = $client;
     }
 
-    public function __call($method, $params = []): ?array
+    public function __call($method, $params = [])
     {
         return $this->client->call($method, ...$params);
     }