Fix CI badge in Readme (#150)

Author: simPod

.github/workflows/php.yml

@@ -1,4 +1,4 @@
-name: Tests
+name: CI
 
 on:
   push:

README.md

@@ -6,7 +6,7 @@ It also provides a CLI tool for validating and converting OpenAPI 3.0.x Descript
 
 [![Latest Stable Version](https://poser.pugx.org/cebe/php-openapi/v/stable)](https://packagist.org/packages/cebe/php-openapi)
 [![Total Downloads](https://poser.pugx.org/cebe/php-openapi/downloads)](https://packagist.org/packages/cebe/php-openapi)
-[![Build Status](https://github.com/cebe/php-openapi/workflows/PHP%20Composer/badge.svg)](https://github.com/cebe/php-openapi/actions)
+[![Build Status](https://github.com/cebe/php-openapi/workflows/CI/badge.svg)](https://github.com/cebe/php-openapi/actions)
 
 
 ## Install