Adding code coverage nuget (#53)

* Adding code coverage nuget, addresses #39

Author: nzthiago

src/APIM_ARMTemplate/apimtemplate.test/apimtemplate.test.csproj

@@ -11,6 +11,10 @@
   </ItemGroup>
 
   <ItemGroup>
+    <PackageReference Include="coverlet.msbuild" Version="2.5.0">
+      <IncludeAssets>runtime; build; native; contentfiles; analyzers</IncludeAssets>
+      <PrivateAssets>all</PrivateAssets>
+    </PackageReference>
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="15.9.0" />
     <PackageReference Include="xunit" Version="2.4.0" />
     <PackageReference Include="xunit.runner.visualstudio" Version="2.4.0" />