Ensure we include the symfony dependency, otherwise fatal errors happ…

…en in the release build. Also run composer install

.gitignore

@@ -2,7 +2,8 @@ node_modules/
 vendor/*
 !vendor/autoload.php
 !vendor/composer
-!vendor/microsoft
 !vendor/guzzlehttp
+!vendor/microsoft
 !vendor/psr
 !vendor/ralouphie
+!vendor/symfony

vendor/autoload.php

@@ -2,6 +2,24 @@
 
 // autoload.php @generated by Composer
 
+if (PHP_VERSION_ID < 50600) {
+    if (!headers_sent()) {
+        header('HTTP/1.1 500 Internal Server Error');
+    }
+    $err = 'Composer 2.3.0 dropped support for autoloading on PHP <5.6 and you are running '.PHP_VERSION.', please upgrade PHP or use Composer 2.2 LTS via "composer self-update --2.2". Aborting.'.PHP_EOL;
+    if (!ini_get('display_errors')) {
+        if (PHP_SAPI === 'cli' || PHP_SAPI === 'phpdbg') {
+            fwrite(STDERR, $err);
+        } elseif (!headers_sent()) {
+            echo $err;
+        }
+    }
+    trigger_error(
+        $err,
+        E_USER_ERROR
+    );
+}
+
 require_once __DIR__ . '/composer/autoload_real.php';
 
 return ComposerAutoloaderInit64f3d7efa5db66253421c9a2cfcb9f32::getLoader();