* Clean up unnecessary workarounds on the build project.
* Remove the need to specify the content root relative to the solution
and use a solution based on an assembly level attribute on the test
assembly created at build time.
* Remove non parameterless constructors.
* Add support for creating specialized factories from the base factory
and keep track of "child" factories for disposal.
* Add support for creating clients that handle cookies and redirects
automatically.
* Detect a ConfigureDefaultBuilder static method on Program.cs of the test site
and use it to initialize the IWebHostBuilder instance that we configure for testing.
* Make use of the new service configuration extensibility points in Hosting to override
services for testing.
* Get rid of MvcWebApplicationBuilder and move MVC specific methods into extension methods.
Javier Calvarro Nelson
Ryan Brandenburg