Serialize the CI

Building Deimos takes up too many resources to run two build jobs at the same time. Therefore I added new stages for the CentOS 7 and 8 build respectively, disabling the Authorisation build because that is rather unimportant anyway.

Changelog:
* Separate test CI stages for CentOS 7 and 8
* Disable 'Authorisation Disabled' test
5 jobs for devel in 25 minutes and 25 seconds (queued for 2 seconds)
latest
Status Name Job ID Coverage
  Static Analysis
passed Format #9549
docker

00:01:24

passed Lint #9550
docker

00:07:58

 
  Build
passed Documentation #9551
docker

00:03:46

 
  Test 8
passed Default #9552
docker

00:04:57

 
  Test 7
passed Centos7 #9553
docker

00:08:43