[Tutorial] Run your own satellite (part 17) - Placement

We have some new keywords:

CreateNodeValue

https://github.com/storj/storj/blob/45bf46c6bb0eef7dc7bc54f40a91a5be0c479463/satellite/nodeselection/node.go#L177

free_disk
piece_count

CreateNodeAttribute

https://github.com/storj/storj/blob/45bf46c6bb0eef7dc7bc54f40a91a5be0c479463/satellite/nodeselection/node.go#L224

last_net
id // or node_id - same thing
last_ip_port
last_ip
wallet
email
country
vetted