use txnbuild assets in compliance (stellar#1426)

use txnbuild assets in compliance (stellar#1426)

Horizon v0.18.1 CHANGELOG (stellar#1427)

Compliance server unit tests (stellar#1417)

* add mocks

* receive handler test

* tx_status tests

* helpers

* wip send test: need txnbuild  base64

* send tests

* auth tests

* auth handler tests

* return transactiion xdr

services/bridge: update changelog (stellar#1419)

* 0.0.32 changelog

* remove deprecated history.Accounts

services/bridge: update changelog (stellar#1419)

* 0.0.32 changelog

* remove deprecated history.Accounts

services/ticker: ensure docker pulls ticker binary from stellar/go re…

…leases (stellar#1378)

Display new fields in Horizon 0.18.0 (stellar#1374)

Display new fields in Horizon 0.18.0 (stellar#1374)

Merge branch 'release-horizon-v0.18.0' of github.com:stellar/go into …

…release-horizon-v0.18.0