actions.yaml and config.yaml are inconsistent about integer types

[John A Meinel]

actions.yaml and config.yaml don't agree whether it should be called "int" or "integer". (one requires one spelling, the other requires the other spelling.)

It would be good for new versions of Juju to allow both, and possibly to warn that it will be incompatible with older versions. But we definitely want to move towards a consistent spelling between both of them. (since we use 'string' I would also use 'integer' as the preferred spelling).

If we choose to support both spellings for the side that currently uses 'int', I think we could do this in a 2.9 release.