Code review comment for lp:~nobuto/charms/trusty/nova-cloud-controller/fix-catch-error

Both IOError and OSError map to FileNotFound depending on whether it is stdlib or os since it is actually a wrapper for ENOENT - https://docs.python.org/3/library/exceptions.html#FileNotFoundError.

So LGTM +1 but non-os calls will need IOError -> FilNotFound.