Add support for authentication via REMOTE_USER

app/Http/Middleware/RemoteUserAuthenticate.php

@@ -0,0 +1,44 @@
+<?php
+
+namespace CachetHQ\Cachet\Http\Middleware;
+
+use CachetHQ\Cachet\Models\User;
+use Closure;
+use Illuminate\Contracts\Auth\Guard;
+use Illuminate\Http\Request;
+
+class RemoteUserAuthenticate
+{
+    /**
+     * Create a new remote user authenticate instance.
+     *
+     * @param \Illuminate\Contracts\Auth\Guard $auth
+     * 
+     * @return void
+     */
+    public function __construct(Guard $auth)
+    {
+        $this->auth = $auth;
+    }
+
+    /**
+     * Handle an incoming request.
+     *
+     * @param \Illuminate\Http\Request $request
+     * @param \Closure                 $next
+     * 
+     * @return mixed
+     */
+    public function handle(Request $request, Closure $next)
+    {
+        if ($remoteUser = $request->server('REMOTE_USER')) {
+            $user = User::where('email', '=', $remoteUser)->first();
+
+            if ($user instanceof User && $this->auth->guest()) {
+                $this->auth->login($user);
+            }
+        }
+
+        return $next($request);
+    }
+}