Added ext-ctype as extension dependency and removed skipping of test

composer.json

@@ -10,6 +10,7 @@
     ],
     "require": {
         "php": "^5.6 || ^7.0",
+        "ext-ctype": "*",
         "ext-hash": "*",
         "ext-mongodb": "^1.2.0",
         "mongodb/mongodb": "^1.0.1"

tests/Alcaeus/MongoDbAdapter/Mongo/MongoClientTest.php

@@ -283,7 +283,6 @@ class MongoClientTest extends TestCase
     {
         $client = new \MongoClient('mongodb://localhost/db?w=0&wtimeout=0', ['connect' => false]);
 
-        $this->skipTestIf(extension_loaded('mongo'));
         $this->assertSame(['w' => 0, 'wtimeout' => 0], $client->getWriteConcern());
     }