title: How to initialize IOption<AppSettings> for unit testing a .NET core MVC service?
body: <p>I have a .NET core MVC rest service. 
  I have a controller I wish to test. This controller has a constructor argument of IOptions where AppSettings is my class for config settings ( I store my database connection string in it). It gets injected from the setup in ConfigureServices in Startup.cs</p>
  
  <p>The rest service works. My problem is I've set up a MSTest test project to test the service. I can't figure out how to initialize an instance of IOptions to satisfy the constructor of my controller.</p>