support for --atomic

[TomaszBelina]

The change adds atomicPush property to plugin configuration. If set to true --atomic option is added to git command line.

[aleksandr-m]

@TomaszBelina Do you have a real use-case for that? For me if some push fails, I would probably resolve it manually and not pushing what is already ok is less work to do.

[mmusenbr]

I would have a use-case for this: CI. We trigger everything via CI. So if eg the merge into dev in the later stage of the process fails, I would not only need to resolve that merge failure, but also cleanup everything what has already happened.
But to keep to current workflow/functionality I would suggest to do it encapsulated in gitPush/gitPushDelete and either store it or push it immediately.

[aleksandr-m]

@redeamer Not sure I understand the need to clean something up after fail. E.g. you are running the goal with two pushes and second one fails, then resolution is probably as simple as resolve conflicts, merge, delete branch. Or maybe creating some PR with hotfix which can be merged in CI.

And even if you do need to do some cleaning, I cannot see how atomic will change this.