Process matching pipelines stages sequentially

[Cyril Auburtin]

For a bitbucket-pipelines like this:

pipelines:
  default:
    - step:
        script:
          - doA
  branches:
    '*':
      - step:
          script:
            - doB # we are here if default ran its steps (doA) successfully
    staging:
      - step:
          script:
            - doC # we are here if default and branches '*' ran their steps (doA then doB) successfully
    production:
      - step:
          script:
            - doC # we are here if default and branches '*' ran their steps (doA then doB) successfully

I'd expect that default is ran every time, whatever follow (currently it's not the case, default is only ran if there's nothing else matching)

I'd also expect that each matching branches pattern are ran, in order (currently only last one is ran) 

You could add a mode: sequential in the pipelines root properties, or at least a `shared`  property under pipelines, ran in all cases

"Pipeline" in Computing means a set of tasks connected in series, that's why the current behavior is confusing

It'd be possible to put everything under `default` and use `BITBUCKET_BRANCH` case conditions, but that's not very readable and not easy in yaml

Thanks

note: the html editor is not working well with code and pasting, Ii had to format this post from the dev console `$0.textContent = `pipelines:...`