Chore: Move to centos8-builder

Chore: Move to centos8-builder

jjb/so/so-adapters-so-etsi-sol003-adapter.yaml
jjb/so/so-adapters-so-etsi-sol005-adapter.yaml
jjb/so/so-adapters-so-nssmf-adapter.yaml
jjb/so/so-adapters-so-oof-adapter.yaml
jjb/so/so-libs.yaml
jjb/so/so-so-admin-cockpit.yaml
jjb/so/so-so-etsi-nfvo.yaml
jjb/so/so.yaml
jjb/testsuite/pythonsdk-tests/testsuite-pythonsdk-tests.yaml
jjb/testsuite/robot-utils/testsuite-robot-utils.yaml
jjb/testsuite/testsuite-cds-mock-odl.yaml
jjb/testsuite/testsuite-cds-mock-server.yaml
jjb/testsuite/testsuite-cds-mock-ssh.yaml
jjb/testsuite/testsuite-cds.yaml
jjb/testsuite/testsuite-oom.yaml

Issue-ID: CIMAN-33
Signed-off-by: Bengt Thuree <bthuree@linuxfoundation.org>
Change-Id: Id4a6714a9dbce8ac7d77c4f332c880077e3b176b