remove duplicate package references

tests/ImageSharp.Sandbox46/ImageSharp.Sandbox46.csproj

@@ -17,11 +17,8 @@
     <ProjectReference Include="..\..\src\ImageSharp\ImageSharp.csproj" />
   </ItemGroup>
   <ItemGroup>
-    <!--<PackageReference Include="Microsoft.NET.Test.Sdk" Version="15.0.0" />-->
-    <PackageReference Include="Moq" Version="4.7.1" />
-    <PackageReference Include="Moq" Version="4.7.99" />
     <PackageReference Include="xunit" Version="2.3.0-beta4-build3742" />
-    <!--<PackageReference Include="xunit.runner.visualstudio" Version="2.2.0" />-->
+    <PackageReference Include="Moq" Version="4.7.99" />
   </ItemGroup>
   <ItemGroup>
     <Compile Include="..\ImageSharp.Tests\**\*.cs" Exclude="bin\**;obj\**" Link="Tests\%(RecursiveDir)%(Filename)%(Extension)" />

tests/ImageSharp.Tests/ImageSharp.Tests.csproj

@@ -17,13 +17,10 @@
   </ItemGroup>
   <ItemGroup>
     <PackageReference Include="CoreCompat.System.Drawing" Version="1.0.0-beta006" />
-    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="15.0.0" />
     <PackageReference Include="xunit" Version="2.3.0-beta4-build3742" />
     <PackageReference Include="xunit.runner.visualstudio" Version="2.3.0-beta4-build3742" />
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="15.3.0" />
     <PackageReference Include="Moq" Version="4.7.99" />
-    <PackageReference Include="xunit" Version="2.3.0-beta4-build3742" />
-    <PackageReference Include="xunit.runner.visualstudio" Version="2.3.0-beta4-build3742" />
     <!--<PackageReference Include="StyleCop.Analyzers" Version="1.1.0-beta001">
       <PrivateAssets>All</PrivateAssets>
     </PackageReference>-->