Update Azure DevOps badge

Signed-off-by: José Simões <[email protected]>

Author: josesimoes

README.md

@@ -13,8 +13,8 @@
 
 | Component | Build Status | NuGet Package |
 |:-|---|---|
-| Core Library | [![Build status](https://ci.appveyor.com/api/projects/status/5b37qa4h0o2ci3db/branch/master?svg=true)](https://ci.appveyor.com/project/nfbot/lib-corelibrary/branch/master) | [![NuGet](https://img.shields.io/nuget/v/nanoFramework.CoreLibrary.svg)](https://www.nuget.org/packages/nanoFramework.CoreLibrary/)  |
-| Core Library (preview) | [![Build Status](https://dev.azure.com/nanoframework/CoreLibrary/_apis/build/status/nanoframework.lib-CoreLibrary)](https://dev.azure.com/nanoframework/CoreLibrary/_build/latest?definitionId=24) | [![MyGet Pre Release](https://img.shields.io/myget/nanoframework-dev/vpre/nanoFramework.CoreLibrary.svg)](https://www.myget.org/feed/nanoframework-dev/package/nuget/nanoFramework.CoreLibrary) |
+| Core Library | [![Build Status](https://dev.azure.com/nanoframework/CoreLibrary/_apis/build/status/nanoframework.lib-CoreLibrary?branchName=develop)](https://dev.azure.com/nanoframework/CoreLibrary/_build/latest?definitionId=24?branchName=master) | [![NuGet](https://img.shields.io/nuget/v/nanoFramework.CoreLibrary.svg)](https://www.nuget.org/packages/nanoFramework.CoreLibrary/)  |
+| Core Library (preview) | [![Build Status](https://dev.azure.com/nanoframework/CoreLibrary/_apis/build/status/nanoframework.lib-CoreLibrary?branchName=develop)](https://dev.azure.com/nanoframework/CoreLibrary/_build/latest?definitionId=24?branchName=develop) | [![MyGet Pre Release](https://img.shields.io/myget/nanoframework-dev/vpre/nanoFramework.CoreLibrary.svg)](https://www.myget.org/feed/nanoframework-dev/package/nuget/nanoFramework.CoreLibrary) |
 
 
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