Add C# based Integration Tests

[stevejgordon]

I have recently been trying with some integration testing on a demo project using the TestServer. This supports firing up the application in memory and hitting endpoints using a client to validate the responses.

See: https://blogs.msdn.microsoft.com/webdev/2017/12/07/testing-asp-net-core-mvc-web-apps-in-memory/

I know we have some Scenario tests written using F#, however I have never run those personally. I know for some they do not load since the F# components need to be installed also. Having reviewed them briefly there seems to be quite a lot of ceremony to configuring the flow.

I therefore suggest we look at introducing some C# based integration tests. These may augment or replace the F# ones. They may be more maintainable for those without an F# background too.

@MisterJames What are you thoughts?

I have a branch with an initial demo of the concept which I could submit a PR for. We could then look to build these over time as part of on-going issues?

[c0g1t8]

I've started implementing a browser based testing project implemented in C#/Selenium/XUnit/Core 2.1. I'm hoping it will address the issues in the AllReady.ScenarioTest project - please see #2345. The project takes no dependencies from any other projects in the AllReady solution.