fix: use Docker PHP-FPM to support sampling in conformance tests (#219)

tests/Conformance/Fixtures/nginx.conf

@@ -0,0 +1,15 @@
+server {
+    listen 80;
+    server_name localhost;
+    root /app;
+
+    location / {
+        try_files $uri /tests/Conformance/server.php$is_args$args;
+    }
+
+    location ~ \.php$ {
+        fastcgi_pass php-fpm:9000;
+        fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
+        include fastcgi_params;
+    }
+}