Move to percentage checking for disk/swap
missing commas
Fix percentages
fix default threshold for root disk
Check disk used percentage is above threshold.

It used to be *free* space. It is now percent in *use*
Swap memory check to use graphite too.
Clarify what disk space check does
Changelog - non backward-compatible changes
Merge pull request #15 from ministryofjustice/percentages

Move to percentage checking for disk/swap