Non-clashing temporary key names

[mrodriguez3313]

There are two needs for this feature:

1. The temporary keys that are created through the getKey() endpoint
2. The keys that users transfer over to us on any given endpoint.

If all the keys go into the ipfs node eventually, then they may definitely have clashing names with a big enough user base.
There may be a need for a DB to hold a relationship of user->key for long term useage. But once it gets imported to the ipfs node, it will still need a non clashing name to be usable. Keys will be constantly rotated out, but will still pose an issue eventually.

[mrodriguez3313]

First version implementation here #28