renamed `ownerHash` to `hoodieId`

Reason is that the new frontend method `hoodie.id()`,
that replaces `hoodie.account.ownerHash`.

To be merged together with https://github.com/hoodiehq/hoodie.js/pull/199
Merge pull request #12 from hoodiehq/owner_hash_is_now_hoodie_id

renamed `ownerHash` to `hoodieId`