v0.2.1 - Wallet Syncer Hotfix

This version is the same as v0.2.0 but includes the hotfix #79 that ensures wallets reconnect to the underlying dcrd node if their connection is closed (for example if the dcrd node is restarted).

This affects dcrlnd nodes that run with an embedded dcrwallet and that remain online for a significant amount of time (i.e. hubs).

Decrediton wallets are not affected by this.

The build artifacts were reproducibly generated by https://github.com/matheusd/release-dcrlnd/