add composer.json

composer.json

+{
+  "name": "drupal/iban_field",
+  "description": "IBAN Field.",
+  "type": "drupal-module",
+  "license": "GPL-2.0+",
+  "homepage": "http://drupal.org/project/iban_field",
+  "authors": [
+  ],
+  "support": {
+    "issues": "https://www.drupal.org/project/issues/iban_field",
+    "source": "https://cgit.drupalcode.org/iban_field"
+  }
+}