feat: add warning if PHP version is too low

rock

@@ -1,12 +1,19 @@
 #!/usr/bin/env php
 <?php
+
 use Symfony\Component\Console\Output\ConsoleOutput;
-require __DIR__.'/vendor/autoload.php';
+
+require __DIR__ . '/vendor/autoload.php';
 $app = new \RockShell\Application();
 $app->registerCommands();
 try {
+  if (version_compare(phpversion(), '8.0', '<')) {
+    throw new Exception(
+      "PHP Version must be at least 8.0 - your version is " . phpversion()
+    );
+  }
   $app->run();
 } catch (\Throwable $th) {
   $output = new ConsoleOutput();
-  $output->writeln("<bg=red;options=bold>".$th->getMessage()."</>");
+  $output->writeln("<bg=red;options=bold>" . $th->getMessage() . "</>");
 }