GitLab

* Update .NET Core to 2.1

* Update IdentityServer4 demo host to .NET Core 2.1.

* Replace @Html.Partial with @await Html.PartialAsync - fix issue #27

* Added DbContext interfaces for EF configuration and operational store

* Update name in license and make it render nicely using MarkDown

* Link to the license from the README

* Update packages and set compatibility to .net core 2.1.

* Update README.md

* Add link for latest .NET Core version