Add a dummy window global with a Date attribute.
Add a dummy window global with a Date attribute.

Workaround until https://github.com/elm-lang/core/commit/e61100cc44c2669f045199fc474fe57a4b0d1c47 gets released.

avh4/node-elm-test,ento/node-elm-test,rtfeldman/node-test-runner,rtfeldman/node-elm-test,ento/node-elm-test,rtfeldman/node-elm-test,avh4/node-elm-test