Fix variable names and update README

Author: apassant

README.md

@@ -172,6 +172,16 @@ $client->leads->scrollLeads();
 
 See [here](https://github.com/intercom/intercom-php#scroll) for more info on using the scroll parameter
 
+## Customers
+
+```php
+/** Search for customers */
+$client->customers->search([
+    "query" => ['field' => 'name', 'operator' => '=', 'value' => 'Alice'],
+    "sort" => ["field" => "name", "order" => "ascending"],
+    "pagination" => ["per_page" => 10]
+]);
+
 ## Visitors
 
 Retrieve `user_id` of a visitor via [the JavaScript API](https://developers.intercom.com/docs/intercom-javascript#section-intercomgetvisitorid)

src/IntercomClient.php

@@ -136,6 +136,7 @@ class IntercomClient
     public function __construct($appIdOrToken, $password = null, $extraRequestHeaders = [])
     {
         $this->users = new IntercomUsers($this);
+        $this->customers = new IntercomCustomers($this);
         $this->events = new IntercomEvents($this);
         $this->companies = new IntercomCompanies($this);
         $this->messages = new IntercomMessages($this);

test/IntercomCustomersTest.php

@@ -7,12 +7,12 @@
 
 class IntercomCustomersTest extends TestCase
 {
-    public function testUserSearch()
+    public function testCustomerSearch()
     {
         $stub = $this->getMockBuilder('Intercom\IntercomClient')->disableOriginalConstructor()->getMock();
         $stub->method('post')->willReturn('foo');
 
-        $users = new IntercomCustomers($stub);
-        $this->assertEquals('foo', $users->search({"query": {}}));
+        $customers = new IntercomCustomers($stub);
+        $this->assertEquals('foo', $customers->search(["query": []]));
     }
 }