Merge pull request #885 from GreenShadeZhang/remove_obsolete_nuget

Remove obsolete nuget packages for BotSharp.Abstraction

Author: Oceania2018

src/Infrastructure/BotSharp.Abstraction/BotSharp.Abstraction.csproj

@@ -24,8 +24,7 @@
   </ItemGroup>
 
   <ItemGroup>
-    <PackageReference Include="Microsoft.AspNetCore.Http.Abstractions" Version="2.2.0" />
-    <PackageReference Include="Microsoft.AspNetCore.StaticFiles" Version="2.2.0" />
+    <FrameworkReference Include="Microsoft.AspNetCore.App" />
     <PackageReference Include="Microsoft.Extensions.Configuration.Binder" Version="8.0.1" />
     <PackageReference Include="Microsoft.Extensions.DependencyInjection.Abstractions" Version="8.0.0" />
     <PackageReference Include="Microsoft.Extensions.Http" Version="8.0.0" />