* Update dotnet version to 3.0.100-preview4-011144. This contains System.Drawing.SystemColors moved to the right place.

* Update dependencies

* Our tests aren't running on the just-produced bits yet. There is a bug in core-sdk that has lead to the ingestion of a new shared framework, but the dependent netcoreapp shared framework hasn't been taken in. This causes all WPF applications to break just now - which also means that our tests are failing for no reason other than the fact that they are WPF apps.

Disabling this now in release/3.0 branch. We will ensure that our tests are run against the right bits as part of the 'testhost' work in 'master'