Method checks if all attachments found in Redis are pinned.

Method deletes one attachment for hash from both IPFS and Redis.

Method deletes record for attachment from Redis. Use this method in
Cleaner.run().

Gendoc script generates docs using jsdoc and concatenates them
with project description into README.md.

This change allows deleted attachments to be garbage collected.

Wrap IPFS pin.add and pin.rm to allow access for other classes.