v2.0.0

[braydonf]

• Implements SIP32 (Hierarchically Deterministic Node IDs) for running a complex with many renters with different nodeIDs but can act on the same contracts.
• Implements SIP4 (Contract Transfers and Renewals) to renew contracts with hd keys.
• Adds 100% test coverage

[super3]

Wish we could keep the renters minions from gaining access to the hd priv key, but guess that is another SIP for another time. Otherwise looks good so far.

[braydonf]

The key derived at index m/3000' isn't accessible, though :)

"...knowledge of the parent extended public key plus any non-hardened private key descending from it is equivalent to knowing the parent extended private key" https://github.com/bitcoin/bips/blob/master/bip-0032.mediawiki#implications

The extended private key here is the one derived at the path m/3000'/0' and each node's key is derived from it at non-hardened path m/3000'/0'/node_index.

[coveralls]

Changes Unknown when pulling be4e85a on braydonf:hdkeys into * on Storj:master*.