Added support for users.admin.setInactive, need advice for integration

[brontolinux]

Hi there

I forked your work and implemented support for users.admin.setInactive and I would like to help you integrate it in your code if you so wish.

users.admin.setInactive is an undocumented method of the Slack API that makes a user inactive. The unofficial documentation says that you need a legacy token in order for it to work, but it actually worked for me using an application I defined on Slack and a OAuth token with the client scope.

I am still learning Go, so in order to test my implementation I couldn't think of anything better than replacing all occurrences of your repo's references with mine and use go get -u to install my package again at each iteration. As a result, many files were changed but the ones that should be actually integrated are only four:

• client.go
• endpoints.json
• interface.go
• services.go

If you wish to integrate my changes I can surely restore the references to your repository and open a pull request, or do anything you suggest to make my changes suitable for integration. Just let me know.

Thanks
-- Marco