Add Icelandic Króna (ISK) to currency seeder

ISK uses 0 decimal precision (no fractional units), dot thousand
separator, comma decimal separator, and symbol after the number.

Fixes #348

database/seeders/CurrenciesTableSeeder.php

@@ -63,6 +63,15 @@ class CurrenciesTableSeeder extends Seeder
                 'decimal_separator' => ',',
                 'swap_currency_symbol' => true,
             ],
+            [
+                'name' => 'Icelandic Króna',
+                'code' => 'ISK',
+                'symbol' => 'kr',
+                'precision' => '0',
+                'thousand_separator' => '.',
+                'decimal_separator' => ',',
+                'swap_currency_symbol' => true,
+            ],
             [
                 'name' => 'Israeli Shekel',
                 'code' => 'ILS',