Updating README.md to mention asp.net core 2 (#25)
Updating README.md to mention asp.net core 2 (#25)

Updating the README.md to mention the asp.net core 2 branch
AzureADSamples/WebApp-OpenIdConnect-AspNet5,Azure-Samples/active-directory-dotnet-webapp-openidconnect-aspnet5,Azure-Samples/active-directory-dotnet-webapp-openidconnect-aspnet5,AzureADSamples/WebApp-OpenIdConnect-AspNet5,Azure-Samples/active-directory-dotnet-webapp-openidconnect-aspnet5,AzureADSamples/WebApp-OpenIdConnect-AspNet5