Nessun eseguibile ha trovato il comando corrispondente “dotnet-ef”

Sto facendo un esempio di progetto utilizzando ASP.Net Core RC2 con Microsoft.EntityFramework.Core e SQLite.

Ho seguito questo tutorial: https://damienbod.com/2015/08/30/asp-net-5-with-sqlite-and-entity-framework-7/

Ma, quando eseguo questo comando:

 dotnet ef migrations add FirstMigration 

Ho ricevuto questo errore:

 No executable found matching command "dotnet-ef" 

Ecco la mia configurazione project.json :

 { "dependencies": { "Microsoft.NETCore.App": { "version": "1.0.0-rc2-3002702", "type": "platform" }, "Microsoft.AspNetCore.Mvc": "1.0.0-rc2-final", "Microsoft.AspNetCore.Server.IISIntegration": "1.0.0-rc2-final", "Microsoft.AspNetCore.Server.Kestrel": "1.0.0-rc2-final", "Microsoft.Extensions.Configuration.EnvironmentVariables": "1.0.0-rc2-final", "Microsoft.Extensions.Configuration.FileExtensions": "1.0.0-rc2-final", "Microsoft.Extensions.Configuration.Json": "1.0.0-rc2-final", "Microsoft.Extensions.Logging": "1.0.0-rc2-final", "Microsoft.Extensions.Logging.Console": "1.0.0-rc2-final", "Microsoft.Extensions.Logging.Debug": "1.0.0-rc2-final", "Microsoft.EntityFrameworkCore": "1.0.0-rc2-final", "Microsoft.EntityFrameworkCore.Sqlite": "1.0.0-rc2-final" }, "tools": { "Microsoft.AspNetCore.Server.IISIntegration.Tools": { "version": "1.0.0-preview1-final", "imports": "portable-net45+win8+dnxcore50" } }, "frameworks": { "netcoreapp1.0": { "imports": [ "dotnet5.6", "dnxcore50", "portable-net45+win8" ] } }, "buildOptions": { "emitEntryPoint": true, "preserveCompilationContext": true }, "runtimeOptions": { "gcServer": true }, "publishOptions": { "include": [ "wwwroot", "Views", "appsettings.json", "web.config" ] }, "scripts": { "postpublish": [ "dotnet publish-iis --publish-folder %publish:OutputPath% --framework %publish:FullTargetFramework%" ] } }