Update internal type correctness unit-test framework to dtslint #77

Historically typesafe-actions was created well before there was any solutions in the wild that would allow to unit-test correctness of resulting type annotations. So I had to improvise and cook my own solution to do that, unfortunately this increased a cost of maintenance and adding new features slowing down development and increasing effort.

I want to fix that now and leverage a really nice solution created by the TypeScript team: https://github.com/Microsoft/dtslint

This will allow to add new features with less effort and also increase the type correctness unit-test coverage.

Planned work:

• remove internal types testing framework
• refactor all existing tests to use dtslint
• optional: check for missing tests to increase coverage