Change tests badge in readme to master branch tests.

Author: runemalm

.github/workflows/tests.yml

@@ -4,6 +4,7 @@ on:
   push:
     branches:
       - develop
+      - master
 
 jobs:
   unit-tests:

README.md

@@ -1,4 +1,4 @@
-[![License](https://img.shields.io/badge/License-GPLv3-blue.svg)](https://www.gnu.org/licenses/gpl-3.0.html) [![NuGet](https://img.shields.io/nuget/v/OpenDDD.NET.svg)](https://www.nuget.org/packages/OpenDDD.NET/) [![Documentation](https://img.shields.io/badge/docs-Read%20the%20Docs-blue.svg)](https://openddd.net) [![Downloads](https://img.shields.io/nuget/dt/OpenDDD.NET.svg)](https://www.nuget.org/packages/OpenDDD/) [![Tests](https://github.com/runemalm/OpenDDD.NET/actions/workflows/tests.yml/badge.svg?branch=develop)](https://github.com/runemalm/OpenDDD.NET/actions/workflows/tests.yml)
+[![License](https://img.shields.io/badge/License-GPLv3-blue.svg)](https://www.gnu.org/licenses/gpl-3.0.html) [![NuGet](https://img.shields.io/nuget/v/OpenDDD.NET.svg)](https://www.nuget.org/packages/OpenDDD.NET/) [![Documentation](https://img.shields.io/badge/docs-Read%20the%20Docs-blue.svg)](https://openddd.net) [![Downloads](https://img.shields.io/nuget/dt/OpenDDD.NET.svg)](https://www.nuget.org/packages/OpenDDD/) [![Tests](https://github.com/runemalm/OpenDDD.NET/actions/workflows/tests.yml/badge.svg?branch=master)](https://github.com/runemalm/OpenDDD.NET/actions/workflows/tests.yml)
 
 
 # OpenDDD.NET