RockMigrations1 - Easy migrations from dev/staging to live server

[bernhard]

I've checked that package and it is <300kB in size. I'd be ok to add that to RockMigrations if someone provides a PR.

Otherwise I think I'll remove the YAML support from the module before I officiallly release the module to avoid confusion.

[netcarver]

The newer versions of symfony/yaml require a pretty recent version of PHP - so you might need to use an older version of that library if you do go down that route.  If you don't need Yaml support, then removing it might be better.