Port the discovery endpoints integration tests

src/OpenIddict.Server.Owin/OpenIddictServerOwinMiddlewareFactory.cs

@@ -9,7 +9,6 @@ using System.Text;
 using System.Threading.Tasks;
 using JetBrains.Annotations;
 using Microsoft.Extensions.DependencyInjection;
-using Microsoft.Extensions.Logging;
 using Microsoft.Extensions.Options;
 using Microsoft.Owin;
 

src/OpenIddict.Validation.Owin/OpenIddictValidationOwinMiddlewareFactory.cs

@@ -9,7 +9,6 @@ using System.Text;
 using System.Threading.Tasks;
 using JetBrains.Annotations;
 using Microsoft.Extensions.DependencyInjection;
-using Microsoft.Extensions.Logging;
 using Microsoft.Extensions.Options;
 using Microsoft.Owin;
 

test/OpenIddict.Server.IntegrationTests/OpenIddict.Server.IntegrationTests.csproj

@@ -24,4 +24,8 @@
     <Reference Include="System.Net.Http" />
   </ItemGroup>
 
+  <PropertyGroup Condition=" '$(TargetFramework)' != 'net461' ">
+    <DefineConstants>$(DefineConstants);SUPPORTS_ECDSA</DefineConstants>
+  </PropertyGroup>
+
 </Project>