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/WordPressValetDriver.php

@@ -0,0 +1,67 @@
+<?php
+
+namespace Valet\Drivers\Specific;
+
+use Valet\Drivers\BasicValetDriver;
+
+class WordPressValetDriver 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 $uri): bool
+    {
+        return file_exists($sitePath.'/wp-config.php') || file_exists($sitePath.'/wp-config-sample.php');
+    }
+
+    /**
+     * Take any steps necessary before loading the front controller for this driver.
+     *
+     * @param  string $sitePath
+     * @param  string $siteName
+     * @param  string $uri
+     * @return void
+     */
+    public function beforeLoading(string $sitePath, string $siteName, string $uri): void
+    {
+        $_SERVER['PHP_SELF'] = $uri;
+        $_SERVER['SERVER_ADDR'] = '127.0.0.1';
+        $_SERVER['SERVER_NAME'] = $_SERVER['HTTP_HOST'];
+    }
+
+    /**
+     * Get the fully resolved path to the application's front controller.
+     *
+     * @param  string  $sitePath
+     * @param  string  $siteName
+     * @param  string  $uri
+     * @return string
+     */
+    public function frontControllerPath(string $sitePath, string $siteName, string $uri): string
+    {
+        return parent::frontControllerPath(
+            $sitePath, $siteName, $this->forceTrailingSlash($uri)
+        );
+    }
+
+    /**
+     * Redirect to uri with trailing slash.
+     *
+     * @param  string  $uri
+     * @return string
+     */
+    private function forceTrailingSlash($uri)
+    {
+        if (substr($uri, -1 * strlen('/wp-admin')) == '/wp-admin') {
+            header('Location: '.$uri.'/');
+            exit;
+        }
+
+        return $uri;
+    }
+}