Issue #668: Sample should be covered by a basic functional test.

#668 - Adding tests for a couple of Controllers in the sample.
yeah that's exactly what I've been suggesting. Just define APIs like this

```
public static readonly string SamplesPath = ...
public static readonly string WebsitesPath = ...

public static IServiceProvider CreateServices(string applicationWebSiteName)
public static IServiceProvider CreateServices(string applicationWebSiteName, string searchPath)
```

Then existing code still works the same way. A test for the samples would call:
```
CreateServices("MvcSample.Web", TestHelper.SamplesPath);
```

Then if we ever need to add more locations, the api doesn't change - you just add a constant.