this patch:
* forces always passing '-r' when pushing after a migration run
* removes '--new-branch' from beta_to_release push. we don't generate new branches on releases anymore because of release promotion!
* has migration runs use a unique share dir for each repo.
this can be used as a stop gap. maybe even a more permanent solution so we don't need to add complexity to robustcheckout for an edgecase like this.
MozReview-Commit-ID: HXY5vDI1pIt
--HG--
extra : rebase_source : 717e48dbf79115817e48adba8ed2f082d832fca0
MozReview-Commit-ID: GD3vspSFmTa
* fix clean_repos. it expects vcs_config key revision but now we use branch
--HG--
extra : rebase_source : d09622ca30eb1c7face42892f149812e5ae5a26a
extra : amend_source : cf7491d93ff2ea9ca13929606368fd443c8f026b