Feature/102 external task helper

[margue]

Pull request for basic external task handling. Provides two helper methods

1. fetchAndLock
2. completeExternalTask

Closes #102

[linus-amg]

hi @margue copy-pasting your code snippets of this PR really helped me testing an external service task, too sad its not yet merged, it works really great. Thank you. 👍

[margue]

Hi @componentdidmount, thank you for the feedback!

@martinschimak, any chances this PR gets merged?

[solo-yolo]

Hi @margue!
Do you have any plans to continue your work on this PR?

[margue]

Hi @solo-yolo, work is done. Just waiting for @martinschimak to review, merge and release it.

[martinschimak]

Hi all. I must ask you to be patient until Camunda takes over the project. As agreed with them, it does not make sense to interfere or publish at the moment.

[zambrovski]

Hi @margue.

Feel free to create a PR against https://github.com/holunda-io/camunda-bpm-assert so we can just release it.

[tmetzke]

Hi all,

thanks to @margue for this contribution, first of all.
We have included this feature in the 3.0.0-alpha1 release based on the code provided here.

Please feel free to try it out and comment on it.

Closing this as merged.

Best,
Tobias