updated changelog

v1.4.0 release adhoc changes

Merge pull request VictorAvelar#55 from VictorAvelar/q1-2020-housekee…

…ping

Q1 2020 housekeeping

Merge pull request VictorAvelar#54 from KamilKulach/master

added missing optional parameter `Payment.SubscriptionID`

Merge pull request VictorAvelar#52 from VictorAvelar/feature/mandates…

…-api-#51

Feature/mandates api VictorAvelar#51

Merge pull request VictorAvelar#50 from VictorAvelar/maintenance/Vict…

…orAvelar#49-api-parity-december-changes

Maintenance/VictorAvelar#49 api parity december changes

Merge pull request VictorAvelar#48 from VictorAvelar/response-closed-…

…error

Response closed error

Merge pull request VictorAvelar#46 from VictorAvelar/housekeeping-11.…

…2019

Housekeeping 11.2019