Added "memory" (array based) cache driver for easier unit testing of application cache operations for developers.

Signed-off-by: Taylor Otwell <taylorotwell@gmail.com>

laravel/cache.php

@@ -56,6 +56,9 @@ class Cache {
 			case 'memcached':
 				return new Cache\Drivers\Memcached(Memcached::connection(), Config::get('cache.key'));
 
+			case 'memory':
+				return new Cache\Drivers\Memory;
+
 			case 'redis':
 				return new Cache\Drivers\Redis(Redis::db());