我正在使用Visual Studio2015进行Udemy课程（与课程相同）

在某些时候，我不得不使用add-migration命令，但不知为什么我做不到。

这是我得到的错误：

我曾搜索过类似的问题，说明我必须安装Microsoft.EntityFrameworkCore.Tools，但当我尝试安装支持添加-迁移命令的版本时，我得到以下错误：

“Microsoft.EntityFrameworkCore.Tools 2.1.0”包需要NuGet客户端版本“3.6.0”或更高版本，但当前的NuGet版本为“3.6.0-RTM-2511”。要升级NuGet，请访问http://docs.NuGet.org/consume/installing-nuget

这是我的project.json文件：

{
  "dependencies": {
    "Microsoft.NETCore.App": {
      "version": "1.0.0",
      "type": "platform"
    },
    "Microsoft.AspNetCore.Diagnostics": "1.0.0",
    "Microsoft.AspNetCore.Mvc": "1.0.0",
    "Microsoft.AspNetCore.Razor.Tools": {
      "version": "1.0.0-preview2-final",
      "type": "build"
    },
    "Microsoft.AspNetCore.Server.IISIntegration": "1.0.0",
    "Microsoft.AspNetCore.Server.Kestrel": "1.0.0",
    "Microsoft.AspNetCore.StaticFiles": "1.0.0",
    "Microsoft.Extensions.Configuration.EnvironmentVariables": "1.0.0",
    "Microsoft.Extensions.Configuration.Json": "1.0.0",
    "Microsoft.Extensions.Logging": "1.0.0",
    "Microsoft.Extensions.Logging.Console": "1.0.0",
    "Microsoft.Extensions.Logging.Debug": "1.0.0",
    "Microsoft.Extensions.Options.ConfigurationExtensions": "1.0.0",
    "Microsoft.EntityFrameworkCore": "1.0.0",
    "Microsoft.EntityFrameworkCore.Tools": {
      "version": "1.0.0-preview2-final",
      "type": "build"
    },
    "Microsoft.VisualStudio.Web.BrowserLink.Loader": "14.0.0",
    "Microsoft.EntityFrameworkCore.SqlServer": "1.0.0",
    "Microsoft.AspNetCore.Identity": "1.0.0",
    "Microsoft.AspNetCore.Authentication.Cookies": "1.0.0",
    "Microsoft.AspNetCore.Identity.EntityFrameworkCore": "1.0.0"
  },
  "tools": {
    "BundlerMinifier.Core": "2.0.238",
    "Microsoft.EntityFrameworkCore.Tools": {
      "version": "1.0.0-preview2-final",
      "imports": [
        "dotnet5.6",
        "portable-net45+win8"
      ]
    },
    "Microsoft.AspNetCore.Razor.Tools": "1.0.0-preview2-final",
    "Microsoft.AspNetCore.Server.IISIntegration.Tools": "1.0.0-preview2-final"
  },
  "frameworks": {
    "netcoreapp1.0": {
      "imports": [
        "dotnet5.6",
        "portable-net45+win8"
      ]
    }
  },
  "buildOptions": {
    "emitEntryPoint": true,
    "preserveCompilationContext": true
  },
  "runtimeOptions": {
    "configProperties": {
      "System.GC.Server": true
    }
  },
  "publishOptions": {
    "include": [
      "wwwroot",
      "Views",
      "Areas/**/Views",
      "appsettings.json",
      "web.config"
    ]
  },
  "scripts": {
    "prepublish": [ "bower install", "dotnet bundle" ],
    "postpublish": [ "dotnet publish-iis --publish-folder %publish:OutputPath% --framework %publish:FullTargetFramework%" ]
  }
}

是否必须直接更改project.json文件中的Microsoft.EntityFrameworkCore.Tools版本？