Added REST API Auth.

[svenrr]

It can be used like this:

`auth = ("username", "password")

ExternalTaskWorker(worker_id="1", config=default_config, base_url=url, rest_auth=auth).subscribe(service_task_topic, handle_task)`

[CLAassistant]

Thank you for your submission! We really appreciate it. Like many open source projects, we ask that you all sign our Contributor License Agreement before we can accept your contribution.
0 out of 3 committers have signed the CLA.

:x: rutscs
:x: svenrr
:x: yogeshrnaik

---

rutscs seems not to be a GitHub user. You need a GitHub account to be able to sign the CLA. If you have already a GitHub account, please add the email address used for this commit to your account.
_{You have signed the CLA already but the status is still pending? Let us recheck it.}

[svenrr]

Thank you for your submission! We really appreciate it. Like many open source projects, we ask that you all sign our Contributor License Agreement before we can accept your contribution. 1 out of 2 committers have signed the CLA.

✅ svenrr ❌ rutscs

rutscs seems not to be a GitHub user. You need a GitHub account to be able to sign the CLA. If you have already a GitHub account, please add the email address used for this commit to your account. You have signed the CLA already but the status is still pending? Let us recheck it.

I have only one github user. Does anyone know how to fix that?

[fliot]

Hi, I must confess I do not understand the branching workflow you are following, REST Api Auth is a very interesting feature, why don't you add it into the master branch ? Please, explain us.

[yogeshrnaik]

Hi, I must confess I do not understand the branching workflow you are following, REST Api Auth is a very interesting feature, why don't you add it into the master branch ? Please, explain us.

Sorry for the delay. Thank you for contributing the REST Auth feature. Please fix the build/tests before merging. Let me know if you need any help.

[celanthe]

Hi there @yogeshrnaik! As these commits are from back in late August, they won't count towards the Camunda Hacktoberfest project. Would you be so kind as to remove the 'hacktoberfest-accepted' issue label?

@rutscs if you would be so kind as to sign the CLA, that would be amazing. Thank you both so much! Alternately, @svenrr or @yogeshrnaik can re-run the CLA bot to remove that user from the automated check if they are no longer a contributor to the project.

[svenrr]

Hi there @yogeshrnaik! As these commits are from back in late August, they won't count towards the Camunda Hacktoberfest project. Would you be so kind as to remove the 'hacktoberfest-accepted' issue label?

@rutscs if you would be so kind as to sign the CLA, that would be amazing. Thank you both so much! Alternately, @svenrr or @yogeshrnaik can re-run the CLA bot to remove that user from the automated check if they are no longer a contributor to the project.

@celanthe I'm also rutscs but I don't know why this name also appears. I just have this github user. @yogeshrnaik can you remove "rutscs" and re-run it?