Remove call to deprecated getMock method

composer.json

@@ -15,7 +15,7 @@
         "mongodb/mongodb": "^1.0.1"
     },
     "require-dev": {
-        "phpunit/phpunit": "^4.8 || ^5.0"
+        "phpunit/phpunit": "^5.4"
     },
     "provide": {
         "ext-mongo": "1.6.13"

tests/Alcaeus/MongoDbAdapter/Mongo/MongoCursorTest.php

@@ -365,6 +365,6 @@ class MongoCursorTest extends TestCase
      */
     protected function getCollectionMock()
     {
-        return $this->getMock('MongoDB\Collection', [], [], '', false);
+        return $this->createMock('MongoDB\Collection', [], [], '', false);
     }
 }