Moved current Router files to API

- updated Unit tests to reflect the change

lib/API/ImportExport.php

@@ -0,0 +1,65 @@
+<?php
+namespace MailPoet\API;
+
+
+use MailPoet\Subscribers\ImportExport\Import\MailChimp;
+use MailPoet\Models\CustomField;
+use MailPoet\Models\Segment;
+
+if(!defined('ABSPATH')) exit;
+
+class ImportExport {
+  function getMailChimpLists($data) {
+    $mailChimp = new MailChimp($data['api_key']);
+    return $mailChimp->getLists();
+  }
+
+  function getMailChimpSubscribers($data) {
+    $mailChimp = new MailChimp($data['api_key']);
+    return $mailChimp->getSubscribers($data['lists']);
+  }
+
+  function addSegment($data) {
+    $segment = Segment::createOrUpdate($data);
+    return (
+      ($segment->id) ?
+        array(
+          'result' => true,
+          'segment' => $segment->asArray()
+        ) :
+        array(
+          'result' => false
+        )
+    );
+  }
+
+  function addCustomField($data) {
+    $customField = CustomField::create();
+    $customField->hydrate($data);
+    $result = $customField->save();
+    return (
+      ($result) ?
+        array(
+          'result' => true,
+          'customField' => $customField->asArray()
+        ) :
+        array(
+          'result' => false
+        )
+    );
+  }
+
+  function processImport($data) {
+    $import = new \MailPoet\Subscribers\ImportExport\Import\Import(
+      json_decode($data, true)
+    );
+    return $import->process();
+  }
+
+  function processExport($data) {
+    $export = new \MailPoet\Subscribers\ImportExport\Export\Export(
+      json_decode($data, true)
+    );
+    return $export->process();
+  }
+}