'Owin.IAppBuilder' does not contain a definition for 'MapSignalR'

Finally was able to solve it by adding signalR dependencies before adding signalR from NuGet Packages
Step's I followed:

1. Added Microsoft.Owin //version 2.0.1
2. Added Microsoft.Owin.Security //version 2.0.1
3. Added Microsoft Asp.Net SignalR

The reason I discovered was a problem with version 2.0.2 of Microsoft.Owin and Microsoft.Owin.Security and then adding a class named Startup.cs with following code:

using Microsoft.Owin;
using Owin;

[assembly: OwinStartup(typeof(webApp.Startup))]
namespace webApp
{
    public static class Startup
    {
        public static void Configuration(IAppBuilder app)
        {
            app.MapSignalR();
        }
    }
}  

Directly adding Microsoft Asp.Net SignalR from NuGet adds version 2.0.2 of Microsoft.Owin and Microsoft.Owin.Security which creates the problem.
Hope it helps someone...!!

Only install this nuget:

Install-Package Microsoft.AspNet.WebApi.OwinSelfHost