Update contributing.md

CONTRIBUTING.md

@@ -27,4 +27,18 @@ The amphp project adheres to the PSR-2 style guide with the exception that
 opening braces for classes and methods must appear on the same line as
 the declaration:
 
-https://github.com/php-fig/fig-standards/blob/master/accepted/PSR-2-coding-style-guide.md
+https://github.com/php-fig/fig-standards/blob/master/accepted/PSR-2-coding-style-guide.md
+
+To apply amphp code standards you can run `php-cs-fixer` with following composer command:
+
+```bash
+composer code-style
+```
+
+## Running the tests
+
+Run the test suite from amphp root directory:
+
+```bash
+composer test
+```

composer.json

@@ -69,5 +69,9 @@
         "platform": {
             "php": "7.0.0"
         }
+    },
+    "scripts": {
+        "test": "@php -dzend.assertions=1 -dassert.exception=1 ./vendor/bin/phpunit",
+        "code-style": "@php ./vendor/bin/php-cs-fixer fix"
     }
 }