Update README.md

Author: Roman Titov

README.md

@@ -22,6 +22,7 @@ Extensions for mocking [Entity Framework Core](https://github.com/dotnet/efcore)
 
 ## ✅ Build & Status
 
+[![codecov](https://codecov.io/github/romantitov/MockQueryable/graph/badge.svg?token=dtiYMUNHUo)](https://codecov.io/github/romantitov/MockQueryable)
 ![.NET Core](https://github.com/romantitov/MockQueryable/workflows/.NET%20Core/badge.svg)
 [![License](https://img.shields.io/github/license/romantitov/MockQueryable.svg)](https://github.com/romantitov/MockQueryable/blob/master/LICENSE)
 
@@ -138,3 +139,4 @@ See the [sample project](https://github.com/romantitov/MockQueryable/tree/master
 
 
 
+