Add SES_REGION to local environment file

The region used by SES was hardcoded into the config file, when all other values were set as environment variables. Tweaked to keep the region consistent with other config options

config/services.php

@@ -22,7 +22,7 @@ return [
     'ses' => [
         'key' => env('SES_KEY'),
         'secret' => env('SES_SECRET'),
-        'region' => 'us-east-1',
+        'region' => env('SES_REGION','us-east-1'),
     ],
 
     'sparkpost' => [