Merge branch 'release/1.6.12' into develop
[#487] Add survey group columns to survey header response

* Add survey group id and name, plus constants false (monitored) and
null registration survey id
* Include this info in both survey header response and surveys-for-phone
response
[#487] Remove whitespace
Merge pull request #489 from akvo/feature/apk_comp

[#487] Add survey group columns to survey header response
[#490] Delete DevicesjobQueue entities

* Query and delete any DevicesjobQueue associated with the assignment
[#490] Remove whitespace
Merge pull request #491 from akvo/feature/issue490

[#490] Delete DevicesjobQueue entities
[#492] Release Notes v1.6.13
[#492] Fix typo in release notes
Merge branch 'release/1.6.13'