Deprecate UsersManager.deleteAll and deleteAllUsers wrapper methods

[M-Zuber]

Fixes #174

[luisrudge]

Thanks for the PR @M-Zuber, but we can't remove this without releasing a new major version. We can, however, mark it as a deprecated method, saying we'll remove it in the next major. Can you change your PR to do that instead?

[M-Zuber]

Sure!

• Is there specific text that should be provided in the deprecation message?
• if it is only being deprecated, should the tests be put back as well?

[luisrudge]

If you want to start a new PR, it might be easier/faster.

An example of a deprecation:

node-auth0/src/management/index.js

Line 1130 in 0cdb074

* @deprecated The function name has a typo.

You can use This method will be removed in the next major. That's fine for now. Thanks! 🎉

[M-Zuber]

I force pushed the changes. Please let me know it anything else needs to be done

[luisrudge]

Thanks 🎉