Removing non-working NuGet downloads statistics badge

Author: asbjornu

README.md

@@ -4,7 +4,6 @@
 Makes it easy to automate git for testing libraries which interact with git. This library was pulled out of [GitVersion](https://github.com/GitTools/GitVersion) so it could be used in other projects.
 
 ![License](https://img.shields.io/github/license/gittools/gittools.core.svg)
-![NuGet downloads](https://img.shields.io/nuget/dt/gittools.testing.svg)
 ![Version](https://img.shields.io/nuget/v/gittools.testing.svg)
 ![Pre-release version](https://img.shields.io/nuget/vpre/gittools.testing.svg)
 [![Build status](https://ci.appveyor.com/api/projects/status/p43k5vdjqldqavag/branch/master?svg=true)](https://ci.appveyor.com/project/GitTools/gittools-testing/branch/master)