[Schematics] Add tests for live schematics and rc of webpack

[endarova]

In current tests we first update everything in the project to rc, that way we don't test the scenario with existing user apps. Add tests that test with latest of schematics and update only webpack to test compatibility with existing apps.

[dtopuzov]

Why test only compatibility with webpack then?
Why not test all combinations of latest plus rc of only one of all packages in order to prove we have capability with all packages?

I'm not against adding such tests, but can we afford running such things on the CI?