Bump PHPUnit to 4.8.36 and use PSR-1 class

composer.json

@@ -16,7 +16,7 @@
         "ext-mongodb": "^1.3.0"
     },
     "require-dev": {
-        "phpunit/phpunit": "^4.8"
+        "phpunit/phpunit": "^4.8.36"
     },
     "autoload": {
         "psr-4": { "MongoDB\\": "src/" },

tests/Model/CachingIteratorTest.php

@@ -4,8 +4,9 @@ namespace MongoDB\Tests\Model;
 
 use MongoDB\Model\CachingIterator;
 use Exception;
+use PHPUnit\Framework\TestCase;
 
-class CachingIteratorTest extends \PHPUnit_Framework_TestCase
+class CachingIteratorTest extends TestCase
 {
     /**
      * Sanity check for all following tests.

tests/PedantryTest.php

@@ -2,6 +2,7 @@
 
 namespace MongoDB\Tests;
 
+use PHPUnit\Framework\TestCase as BaseTestCase;
 use RecursiveDirectoryIterator;
 use RecursiveIteratorIterator;
 use ReflectionClass;
@@ -11,7 +12,7 @@ use RegexIterator;
 /**
  * Pedantic tests that have nothing to do with functional correctness.
  */
-class PedantryTest extends \PHPUnit_Framework_TestCase
+class PedantryTest extends BaseTestCase
 {
     /**
      * @dataProvider provideProjectClassNames

tests/TestCase.php

@@ -5,10 +5,11 @@ namespace MongoDB\Tests;
 use MongoDB\Driver\ReadConcern;
 use MongoDB\Driver\ReadPreference;
 use MongoDB\Driver\WriteConcern;
+use PHPUnit\Framework\TestCase as BaseTestCase;
 use ReflectionClass;
 use stdClass;
 
-abstract class TestCase extends \PHPUnit_Framework_TestCase
+abstract class TestCase extends BaseTestCase
 {
     public function provideInvalidDocumentValues()
     {