add samples project of kafka.

samples/Sample.Kafka/Controllers/ValuesController.cs

@@ -2,8 +2,8 @@
 using System.Collections.Generic;
 using System.Linq;
 using System.Threading.Tasks;
-using Cap.Consistency.Attributes;
 using Cap.Consistency.Consumer;
+using Cap.Consistency.Kafka;
 using Microsoft.AspNetCore.Mvc;
 
 namespace Sample.Kafka.Controllers

samples/Sample.Kafka/Sample.Kafka.csproj

@@ -17,6 +17,7 @@
     <DotNetCliToolReference Include="Microsoft.VisualStudio.Web.CodeGeneration.Tools" Version="1.0.1" />
   </ItemGroup>
   <ItemGroup>
+    <ProjectReference Include="..\..\src\Cap.Consistency.Kafka\Cap.Consistency.Kafka.csproj" />
     <ProjectReference Include="..\..\src\Cap.Consistency\Cap.Consistency.csproj" />
   </ItemGroup>