#61 - feature: new action to facilitate cascade merging when no conflicts exist.

[jdaugherty]

Implements #61

@jamesfredley @matrei I plan to use this to keep our branches in sync on grails-core so there's less manual effort keeping versions in sync (where there's no merge conflict)

[matrei]

This would save a lot of work.

I'm just a little worried that it will merge changes up that are not meant to be merged up.

There is the [skip merge] label (which name I think is to general, maybe [skip merge-up]?), but random people contributing will not know about this label. I puts a burden on the reviewer to also remember and think of this aspect.

[jdaugherty]

@matrei the merge issue exists already today. We can always revert or review the merge as part of the release process. Technically, if you define the ordering backwards, it would support merge down too - that's why I didn't say merge-up or merge-down. Would skip merge-cascade make more sense then?

[jdaugherty]

Also, I've been doing these merges for over a year now without issue so I'm proposing this automation to eliminate that manual task.