More robust deadline handling for a heavily-loaded LND node

Bump go, lnd, lndclient deps

Merge pull request #120 from Jontified/add-wt-metrics

Add watchtower client number of backup metrics

Merge pull request #117 from calvinrzachman/payment-collector

collectors: distinguish attempts by payment status

Merge pull request #116 from calvinrzachman/testnet4

config: add support for testnet4

Merge pull request #115 from calvinrzachman/payment-collector

collectors: collect payment and attempt counts

Merge pull request #113 from bitromortac/2410-inbound-fees

inbound fees: collect and display stats

lndmon v0.2.8