Updated README. Fixed phpunit dependency.

Author: ekyna

CHANGELOG.md

@@ -5,20 +5,26 @@ CHANGELOG for 1.5
     * __Sha256__ is now the <ins>default hash algorithm</ins> used to generate signature. If you still want to use __Sha1__ (previously the default algorithm for SYSTEMPAY endpoint), you must update the API config:
 
         #### Before
-      
-            $config = [
-                'site_id'     => ' ... ',
-                'certificate' => ' ... ',
-                'ctx_mode'    => Api::MODE_PRODUCTION,
-                'directory'   => ' ... ',
-            ];
-      
+
+        ```php
+        $factory = new PayzenGatewayFactory();
+        $gateway = $factory->create([
+            'site_id'     => ' ... ',
+            'certificate' => ' ... ',
+            'ctx_mode'    => Api::MODE_PRODUCTION,
+            'directory'   => ' ... ',
+        ]);
+        ```
+
         #### After
-      
-            $config = [
-                'site_id'     => ' ... ',
-                'certificate' => ' ... ',
-                'ctx_mode'    => Api::MODE_PRODUCTION,
-                'directory'   => ' ... ',
-                'hash_mode'   => Api::HASH_MODE_SHA1, // Add this entry
-            ];
+
+        ```php
+        $factory = new PayzenGatewayFactory();
+        $gateway = $factory->create([
+            'site_id'     => ' ... ',
+            'certificate' => ' ... ',
+            'ctx_mode'    => Api::MODE_PRODUCTION,
+            'directory'   => ' ... ',
+            'hash_mode'   => Api::HASH_MODE_SHA1, // Add this entry
+        ]);
+        ```

README.md

@@ -1,7 +1,29 @@
 PayumPayzen
 ===========
 
-PayZen Payum Gateway
+PayZen Payum Gateway (Systempay, Scellius)
+
+[![Build Status][ico-github-actions]][link-github-actions]
 
 ## Installation / Configuration
-TODO
+
+```bash
+composer require ekyna/payum-payzen
+```
+
+```php
+use Ekyna\Component\Payum\Payzen\Api\Api;
+use Ekyna\Component\Payum\Payzen\PayzenGatewayFactory;
+
+$factory = new PayzenGatewayFactory();
+
+$gateway = $factory->create([
+    'site_id'     => '132456',
+    'certificate' => '132456',
+    'ctx_mode'    => Api::MODE_PRODUCTION,
+    'directory'   => __DIR__ . '/payzen-cache',
+]);
+
+// Register your convert payment action
+// $gateway->addAction(new \Acme\ConvertPaymentAction());
+```

composer.json

@@ -28,7 +28,7 @@
         "psr/log": "^1.0"
     },
     "require-dev": {
-        "phpunit/phpunit": "^8"
+        "phpunit/phpunit": "^7.0|^8.0"
     },
     "autoload": {
         "psr-4": {