Mock/fake version of UnleashClient

[acsbendi]

Describe the feature request

Similarly to the Java library's FakeUnleash, it would be useful to have an official way to easily mock the UnleashClient of this library.

Background

We would like to set enabled feature toggles from integration tests without having to implement a FakeClient in our own code.

Solution suggestions

Similarly to the Java version: define common interface, FakeUnleash implements it too, and it uses a completely local state so that enabled feature toggles can be set from the code.

[gastonfournier]

Hi @acsbendi, thanks for the suggestion. It would be nice to have, but unfortunately not in our priorities at this moment. We'd be happy to review and provide support in case you want to make a contribution.