Merge branch 'v4-prepare' into master

Author: phnx47

README.md

@@ -1,12 +1,9 @@
 # Prometheus.Client.MetricServer
 
-[![MyGet](https://img.shields.io/myget/prometheus-client-net/vpre/Prometheus.Client.MetricServer.svg?label=myget)](https://www.myget.org/feed/prometheus-client-net/package/nuget/Prometheus.Client.MetricServer)
 [![NuGet](https://img.shields.io/nuget/v/Prometheus.Client.MetricServer.svg)](https://www.nuget.org/packages/Prometheus.Client.MetricServer)
 [![NuGet](https://img.shields.io/nuget/dt/Prometheus.Client.MetricServer.svg)](https://www.nuget.org/packages/Prometheus.Client.MetricServer)
+[![CI](https://github.com/PrometheusClientNet/Prometheus.Client.MetricServer/workflows/CI/badge.svg)](https://github.com/PrometheusClientNet/Prometheus.Client.MetricServer/actions?query=workflow%3ACI)
 [![Gitter](https://img.shields.io/gitter/room/PrometheusClientNet/community.svg)](https://gitter.im/PrometheusClientNet/community)
-
-[![Build status](https://ci.appveyor.com/api/projects/status/ea3w0pycgyqqwd1o/branch/master?svg=true)](https://ci.appveyor.com/project/PrometheusClientNet/prometheus-client-metricserver/branch/master)
-[![AppVeyor tests](https://img.shields.io/appveyor/tests/PrometheusClientNet/prometheus-client-metricserver.svg)](https://ci.appveyor.com/project/PrometheusClientNet/prometheus-client-metricserver/build/tests)
 [![License MIT](https://img.shields.io/badge/license-MIT-green.svg)](https://opensource.org/licenses/MIT)
 
 Extension for [Prometheus.Client](https://github.com/PrometheusClientNet/Prometheus.Client)
@@ -32,7 +29,7 @@ static void Main(string[] args)
     metricServer.Start();
     ...
 
-    var counter = Metrics.CreateCounter("test_count", "helptext");
+    var counter =  Metrics.DefaultFactory.CreateCounter("test_count", "helptext");
     counter.Inc();
     ...