Releasing v6.0.28_nginx-1.21.6

This is essentially v6.0.28 but with an uplifted nginx version and
no other changes.

v6.0.32

* Update github token in travis build

v6.0.31

* Add maven group configuration to root build.

v6.0.30

* Add missing nexusPublishing configuration in gradle build.

v6.0.29

* Change Maven group ID to `uk.gov.gchq.stroom.auth` for published libs.

* Uplift node version (10) used in build.

* Change auth-ui docker image base to `nginx:1.20.0-alpine`

v6.0.28

* Uplift mysql connector to 8.0.19 (works with server 5.6, 5.7 & 8)

v6.0.27-4

* NO CHANGES (Build failure)

v6.0.27-3

* NO CHANGES (Build failure)

v6.0.27-2

* Fix missing aud in created tokens.

v7.0-beta.6

* Merged Stroom 6 compatibility