Proper setup of project.json for just .Net Core in RC2?

With the release of .Net Core RC2 I have started rebuilding my website with it and after creating a web application I opened the `project.json` file so I could remove references to the older .Net versions but I am not sure which ones to leave in for just the .Net Core on a Windows IIS (Azure/Windows 2012R2). By default the file config looks like this:

"dependencies": {"Microsoft.NETCore.App": {"version": "1.0.0-rc2-3002702","type": "platform"
    },"Microsoft.AspNetCore.Server.IISIntegration": "1.0.0-rc2-final","Microsoft.AspNetCore.Server.Kestrel": "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"
      ]
    }
  },

I know `dotnet5.6` is an older .Net (I think 4.6?). but what is the `portable-net45+win8`? Is that safe to remove? And do I need to change the imported tool to something else so it only imports tools for .Net Core and not 4.5/win8?