diff --git a/AmazonPay/Client.php b/AmazonPay/Client.php
index 3fe372c..9a8910e 100644
--- a/AmazonPay/Client.php
+++ b/AmazonPay/Client.php
@@ -7,17 +7,6 @@
  * returns Response Object
  */
 
-require_once 'ResponseParser.php';
-require_once 'HttpCurl.php';
-require_once 'ClientInterface.php';
-require_once 'Regions.php';
-if (!interface_exists('\Psr\Log\LoggerAwareInterface')) {
-    require_once(__DIR__.'/../Psr/Log/LoggerAwareInterface.php');
-}
-
-if (!interface_exists('\Psr\Log\LoggerInterface')) {
-    require_once(__DIR__.'/../Psr/Log/LoggerInterface.php');
-}
 use Psr\Log\LoggerAwareInterface;
 use Psr\Log\LoggerInterface;
 
diff --git a/AmazonPay/HttpCurl.php b/AmazonPay/HttpCurl.php
index df281b2..ed8a76b 100644
--- a/AmazonPay/HttpCurl.php
+++ b/AmazonPay/HttpCurl.php
@@ -5,8 +5,6 @@
  * Handles Curl POST function for all requests
  */
 
-require_once 'HttpCurlInterface.php';
-
 class HttpCurl implements HttpCurlInterface
 {
     private $config = array();
diff --git a/AmazonPay/IpnHandler.php b/AmazonPay/IpnHandler.php
index 3b4df8a..86f763d 100644
--- a/AmazonPay/IpnHandler.php
+++ b/AmazonPay/IpnHandler.php
@@ -1,4 +1,5 @@
 <?php
+
 namespace AmazonPay;
 
 /* Class IPN_Handler
@@ -6,14 +7,6 @@
  * verifies that the IPN is from the right resource and has the valid data
  */
 
-require_once 'HttpCurl.php';
-require_once 'IpnHandlerInterface.php';
-if (!interface_exists('\Psr\Log\LoggerAwareInterface')) {
-    require_once(__DIR__.'/../Psr/Log/LoggerAwareInterface.php');
-}
-if (!interface_exists('\Psr\Log\LoggerInterface')) {
-    require_once(__DIR__.'/../Psr/Log/LoggerInterface.php');
-}
 use Psr\Log\LoggerAwareInterface;
 use Psr\Log\LoggerInterface;
 
diff --git a/AmazonPay/Regions.php b/AmazonPay/Regions.php
index e8b1055..66b94ce 100644
--- a/AmazonPay/Regions.php
+++ b/AmazonPay/Regions.php
@@ -1,4 +1,5 @@
 <?php
+
 namespace AmazonPay;
 
 /* Class Regions
diff --git a/AmazonPay/ResponseParser.php b/AmazonPay/ResponseParser.php
index 8e5978b..56ed90b 100644
--- a/AmazonPay/ResponseParser.php
+++ b/AmazonPay/ResponseParser.php
@@ -1,12 +1,11 @@
 <?php
+
 namespace AmazonPay;
 
 /* ResponseParser
  * Methods provided to convert the Response from the POST to XML, Array or JSON
  */
 
-require_once 'ResponseInterface.php';
-
 class ResponseParser implements ResponseInterface
 {
     public $response = null;
diff --git a/composer.json b/composer.json
index 2c88451..770693b 100644
--- a/composer.json
+++ b/composer.json
@@ -22,7 +22,13 @@
    ],
    "autoload": {
       "psr-4": {
-         "AmazonPay\\": "AmazonPay/"
+         "AmazonPay\\": "AmazonPay/",
+         "Psr\\": "Psr/"
+      }
+   },
+   "autoload-dev": {
+      "psr-4": {
+         "AmazonPayTest\\":"test/"
       }
    },
    "require": {
diff --git a/phpunit.xml b/phpunit.xml
new file mode 100644
index 0000000..47aced5
--- /dev/null
+++ b/phpunit.xml
@@ -0,0 +1,11 @@
+<phpunit
+        xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+        xsi:noNamespaceSchemaLocation="http://schema.phpunit.de/3.7/phpunit.xsd"
+        verbose="true"
+        checkForUnintentionallyCoveredCode="true">
+    <testsuites>
+        <testsuite name="Test Amazon Pay Sdk PHP">
+            <directory>Test/Unit</directory>
+        </testsuite>
+    </testsuites>
+</phpunit>
\ No newline at end of file
diff --git a/tst/unit/ClientTest.php b/test/Unit/ClientTest.php
similarity index 99%
rename from tst/unit/ClientTest.php
rename to test/Unit/ClientTest.php
index 9345b23..14d3a71 100644
--- a/tst/unit/ClientTest.php
+++ b/test/Unit/ClientTest.php
@@ -1,9 +1,9 @@
 <?php
-namespace AmazonPay;
 
-require_once 'AmazonPay/Client.php';
-require_once 'AmazonPay/ResponseParser.php';
-require_once 'Signature.php';
+namespace AmazonPayTest\Unit;
+
+use AmazonPay\Client;
+use AmazonPay\ResponseParser;
 
 class ClientTest extends \PHPUnit_Framework_TestCase
 {
@@ -94,7 +94,7 @@ public function testConfigArray()
 
     public function testJsonFile()
     {
-        $configParams = "tst/unit/config/sandbox_true_bool.json";
+        $configParams = "test/Unit/config/sandbox_true_bool.json";
         $client = new Client($configParams);
 
         $this->assertTrue((bool)$client->__get('sandbox'));
@@ -108,22 +108,22 @@ public function testJsonFile()
         $this->assertEquals('1.0', $client->__get('application_version'));
 
         try {
-            $configParams = "tst/unit/config/sandbox_true_string.json";
+            $configParams = "test/Unit/config/sandbox_true_string.json";
             $client = new Client($configParams);
         } catch (\Exception $expected) {
             $this->assertRegExp('/should be a boolean value/i', strval($expected));
         }
 
-        $configParams = "tst/unit/config/sandbox_false_bool.json";
+        $configParams = "test/Unit/config/sandbox_false_bool.json";
         $client = new Client($configParams);
         $this->assertFalse((bool)$client->__get('sandbox'));
 
-        $configParams = "tst/unit/config/sandbox_none.json";
+        $configParams = "test/Unit/config/sandbox_none.json";
         $client = new Client($configParams);
         $this->assertFalse((bool)$client->__get('sandbox'));
 
         try {
-            $configParams = "tst/unit/config/sandbox_false_string.json";
+            $configParams = "test/unit/config/sandbox_false_string.json";
             $client = new Client($configParams);
         } catch (\Exception $expected) {
             $this->assertRegExp('/should be a boolean value/i', strval($expected));
diff --git a/tst/unit/IpnHandlerTest.php b/test/Unit/IpnHandlerTest.php
similarity index 98%
rename from tst/unit/IpnHandlerTest.php
rename to test/Unit/IpnHandlerTest.php
index 5c5cea4..875ffe0 100644
--- a/tst/unit/IpnHandlerTest.php
+++ b/test/Unit/IpnHandlerTest.php
@@ -1,7 +1,8 @@
 <?php
-namespace AmazonPay;
 
-require_once 'AmazonPay/IpnHandler.php';
+namespace AmazonPayTest\Unit;
+
+use AmazonPay\IpnHandler;
 
 class IpnHandlertest extends \PHPUnit_Framework_TestCase
 {
diff --git a/tst/unit/Signature.php b/test/Unit/Signature.php
similarity index 99%
rename from tst/unit/Signature.php
rename to test/Unit/Signature.php
index 02a6727..1d3879e 100644
--- a/tst/unit/Signature.php
+++ b/test/Unit/Signature.php
@@ -1,5 +1,6 @@
 <?php
-namespace AmazonPay;
+
+namespace AmazonPayTest\Unit;
 
 class Signature
 {
diff --git a/tst/unit/config/sandbox_false_bool.json b/test/Unit/config/sandbox_false_bool.json
similarity index 100%
rename from tst/unit/config/sandbox_false_bool.json
rename to test/Unit/config/sandbox_false_bool.json
diff --git a/tst/unit/config/sandbox_false_string.json b/test/Unit/config/sandbox_false_string.json
similarity index 100%
rename from tst/unit/config/sandbox_false_string.json
rename to test/Unit/config/sandbox_false_string.json
diff --git a/tst/unit/config/sandbox_none.json b/test/Unit/config/sandbox_none.json
similarity index 100%
rename from tst/unit/config/sandbox_none.json
rename to test/Unit/config/sandbox_none.json
diff --git a/tst/unit/config/sandbox_true_bool.json b/test/Unit/config/sandbox_true_bool.json
similarity index 100%
rename from tst/unit/config/sandbox_true_bool.json
rename to test/Unit/config/sandbox_true_bool.json
diff --git a/tst/unit/config/sandbox_true_string.json b/test/Unit/config/sandbox_true_string.json
similarity index 100%
rename from tst/unit/config/sandbox_true_string.json
rename to test/Unit/config/sandbox_true_string.json