Add a .gnupg directory for duplicity; .inputrc optionally

The backup/recovery program 'duplicity' has an annoying bug
where it will create .gnupg with the wrong ownership if you recover
with 'sudo'.

This adds the directory with the right ownership, which fixes the
problem.

Also added the optional ability to enable vi editing mode via .inputrc
Merge pull request #6 from ministryofjustice/vim_and_gnupg

Add a .gnupg directory for duplicity; .inputrc optionally