Add namespace for all tests

Author: clue

tests/AllTest.php

@@ -1,5 +1,7 @@
 <?php
 
+namespace React\Tests\Promise\Stream;
+
 use React\Promise\Stream;
 use React\Stream\ThroughStream;
 

tests/BufferTest.php

@@ -1,5 +1,7 @@
 <?php
 
+namespace React\Tests\Promise\Stream;
+
 use Clue\React\Block;
 use React\EventLoop\Factory;
 use React\Promise\Stream;

tests/FirstTest.php

@@ -1,5 +1,7 @@
 <?php
 
+namespace React\Tests\Promise\Stream;
+
 use React\Promise\Stream;
 use React\Stream\ThroughStream;
 

tests/UnwrapReadableTest.php

@@ -1,5 +1,7 @@
 <?php
 
+namespace React\Tests\Promise\Stream;
+
 use Clue\React\Block;
 use React\EventLoop\Factory;
 use React\Promise;

tests/UnwrapWritableTest.php

@@ -1,5 +1,7 @@
 <?php
 
+namespace React\Tests\Promise\Stream;
+
 use Clue\React\Block;
 use React\EventLoop\Factory;
 use React\Promise;

tests/bootstrap.php

@@ -1,8 +1,10 @@
 <?php
 
+namespace React\Tests\Promise\Stream;
+
 require_once __DIR__ . '/../vendor/autoload.php';
 
-class TestCase extends PHPUnit_Framework_TestCase
+class TestCase extends \PHPUnit_Framework_TestCase
 {
     protected function expectCallableOnce()
     {
@@ -51,7 +53,7 @@ protected function expectCallableNever()
      */
     protected function createCallableMock()
     {
-        return $this->getMock('CallableStub');
+        return $this->getMock('React\Tests\Promise\Stream\CallableStub');
     }
 
     protected function expectPromiseResolve($promise)