get next and prev trade aggregations (stellar#1581)

services/ticker: prepare for v1.1.0 release (stellar#1531)

* Update CHANGELOG and ticker version

* Remove temporary functions that were used to address a CMC problem

Store ingestion system version (stellar#1536)

Store ingestion system version (stellar#1536)

horizonclient-v1.3.0-update-changelogs

horizonclient: update changelogs

use txnbuild assets in compliance (stellar#1426)

use txnbuild assets in compliance (stellar#1426)

Horizon v0.18.1 CHANGELOG (stellar#1427)

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