Updated ContextTool to not add custom IConfigureHosting
Making Karl be an IPilkington.

Disabling flaky Redis tests.
Updated unit tests to get services/context in consistent way

All tests now using TestHelpers to create service provider and/or context and/or scoped context services. Tests that use this mechanism run isolated from each other and are quite resilient to internal refactoring. Also updated MigratorTest per issue #1050