Fix table name not being used and migration error (#36)

* Fix table name not being used

The pennant config is using `stores` and same when creating driver in this file, however, when configuring database driver, it reads from `drivers` which is not found.

* Remove migration file registration

According to the docs, we were asked to run `php artisan vendor:publish --provider="Laravel\Pennant\PennantServiceProvider"` and the migration will be published to the base `database/migrations` directory.

And after that when we run `php artisan migrate`, both migration files will be ran and causes error.

src/FeatureManager.php

@@ -77,7 +77,7 @@ public function createArrayDriver()
      */
     public function createDatabaseDriver()
     {
-        return with($this->container['config']->get('pennant.drivers.database'), function ($config) {
+        return with($this->container['config']->get('pennant.stores.database'), function ($config) {
             return new DatabaseDriver(
                 $this->container['db']->connection($config['connection'] ?? null),
                 $this->container['events'],

src/PennantServiceProvider.php

@@ -79,8 +79,6 @@ protected function listenForEvents()
      */
     protected function offerPublishing()
     {
-        $this->loadMigrationsFrom(__DIR__.'/../database/migrations');
-
         $this->publishes([
             __DIR__.'/../config/pennant.php' => config_path('pennant.php'),
         ], 'pennant-config');