Update drivers location and loading

- Extract much of server.php into a `Server` class
- Move all but the Laravel and Basic drivers into a subfolder
- Load all but the Laravel and Basic drivers via glob
- Add `beforeLoading` hook to simplify the `frontControllerPath` method for some drivers

cli/Valet/Drivers/Specific/SculpinValetDriver.php

@@ -0,0 +1,61 @@
+<?php
+
+namespace Valet\Drivers\Specific;
+
+use Valet\Drivers\BasicValetDriver;
+
+class SculpinValetDriver extends BasicValetDriver
+{
+    /**
+     * Determine if the driver serves the request.
+     *
+     * @param  string  $sitePath
+     * @param  string  $siteName
+     * @param  string  $uri
+     * @return bool
+     */
+    public function serves(string $sitePath, string $siteName, string $uri): bool
+    {
+        return $this->isModernSculpinProject($sitePath) ||
+            $this->isLegacySculpinProject($sitePath);
+    }
+
+    private function isModernSculpinProject($sitePath)
+    {
+        return is_dir($sitePath.'/source') &&
+            is_dir($sitePath.'/output_dev') &&
+            $this->composerRequiresSculpin($sitePath);
+    }
+
+    private function isLegacySculpinProject($sitePath)
+    {
+        return is_dir($sitePath.'/.sculpin');
+    }
+
+    private function composerRequiresSculpin($sitePath)
+    {
+        if (! file_exists($sitePath.'/composer.json')) {
+            return false;
+        }
+
+        $composer_json_source = file_get_contents($sitePath.'/composer.json');
+        $composer_json = json_decode($composer_json_source, true);
+
+        if (json_last_error() !== JSON_ERROR_NONE) {
+            return false;
+        }
+
+        return isset($composer_json['require']['sculpin/sculpin']);
+    }
+
+    /**
+     * Mutate the incoming URI.
+     *
+     * @param  string  $uri
+     * @return string
+     */
+    public function mutateUri(string $uri): string
+    {
+        return rtrim('/output_dev'.$uri, '/');
+    }
+}