Use valid name in concourse pipelines

[o-orand]

Expected behavior

As an Ops,
In order to have smooth pipeline deployments
I expect no warning message from concourse on pipelines loading

Observed behavior

During pipelines loading, we have some deprecation warning.

Affected release

Reproduced on version 5.0 and head

Traces and logs

Sample off deprecation warning:

DEPRECATION WARNING:

  - resources.openstack-kvm-ubuntu-xenial-go_agent: 'openstack-kvm-ubuntu-xenial-go_agent' is not a valid identifier: illegal character '_'

  - jobs.compile-and-export-cf-cli.plan.do[0].in_parallel.steps[2].get(openstack-kvm-ubuntu-xenial-go_agent): 'openstack-kvm-ubuntu-xenial-go_agent' is not a valid identifier: illegal character '_'