Error in installing Nuget Package Microsoft.AspNet.WebApi.Cors in Web API2 application - Unable to load the service index for source

I am trying to install Microsoft.AspNet.WebApi.Cors package to impliment CORS in my Web API application.I am using below command to install package:

Install-Package Microsoft.AspNet.WebApi.Cors

But it's giving me following Error:

Install-Package : Unable to load the service index for source >https://api.nuget.org/v3/index.json. At line:1 char:16+ Install-Package <<<< Microsoft.AspNet.WebApi.Cors+ CategoryInfo : NotSpecified: (:) [Install-Package], Exception+ FullyQualifiedErrorId : NuGetCmdletUnhandledException,NuGet.PackageManagement.PowerShellCmdlets.Install>PackageCommand

I am using visual studio 2015 and .net framework 4.5.1 in my project.When I run Get-Package -ListAvailable in package manager console it shows:

No packages found in the current package source.