GoCD not supported in newer versions

[cburgmer]

GoCD has deprecated/removed quite a few API versions, and in one case removed a whole resource altogether. To bring the GoCD sync into 2021 probably all endpoints need to be revised:

Endpoint	Changed in	New Endpoint/New version
/go/api/jobs/:job_id.xml	v20.1.0	/go/api/feed/pipelines/:pipeline_name/:pipeline_counter/:stage_name/:stage_counter/:job_name.xml
/go/api/stages/:pipeline_name/:stage_name/history[/:offset]	v20.9.0	/go/api/stages/:pipeline_name/:stage_name/history v3
/go/api/pipelines/:pipeline_name/instance/:pipeline_counter	v20.1.0	/go/api/pipelines/:pipeline_name/:pipeline_counter v1
/go/api/config/pipeline_groups	20.3.0	removed or replaced by /go/api/admin/pipeline_groups ?