+ 5.4 support

Author: DeadeyeBro

src/Ignited/LaravelOmnipay/BaseServiceProvider.php

@@ -27,13 +27,12 @@ public function register()
      */
     public function registerManager()
     {
-        $this->app['omnipay'] = $this->app->share(function($app)
-        {
-            $factory = new GatewayFactory;
+		$this->app->singleton('omnipay', function ($app) {
+			$factory = new GatewayFactory;
             $manager = new LaravelOmnipayManager($app, $factory);
 
             return $manager;
-        });
+		});
     }
 
     /**