Unconfirmed coinbase transactions will be rebroadcast

[braydonf]

Versions
bcoin v1.0.2

Expected

Resending pending transactions to not broadcast coinbase transactions that will get a node banned from peers.

Actual

If there is a reorg that causes a coinbase transaction to become unconfirmed/pending and the wallet resends any pending transactions to peers, it will attempt to broadcast the coinbase transaction.

Solution

In lib/wallet/wallet.js check that a transaction !wtx.tx.isCoinbase() before adding to the array of transactions to be rebroadcast. This has been fixed in #605 with braydonf@3e65f93#diff-10775d9a238b8247721a7dc0600d5a8a