Release compatible with Core 3.0

Author: ENikS

src/Unity.Microsoft.DependencyInjection.csproj

@@ -51,7 +51,7 @@
 
   <ItemGroup>
     <PackageReference Include="Microsoft.AspNetCore.Hosting.Abstractions" Version="2.2.0" />
-    <PackageReference Include="Microsoft.Extensions.DependencyInjection.Abstractions" Version="3.1.0" /> 
+    <PackageReference Include="Microsoft.Extensions.DependencyInjection.Abstractions" Version="3.0.0" /> 
   </ItemGroup>
 
   <!-- Sourcelink -->