Closes#12927Closes#12958
This PR updates the version of redis used in our examples from 3.2 to 7.
The old version is very not supported anymore, and we should be setting
a good example by using a supported version.
The long-form example job is now fixed so that the service stanza uses
nomad as the service discovery provider, and so now the job runs without
a requirement of having Consul running and configured.
notably:
- name of the compiled binary is 'nomad-device-nvidia', not 'nvidia-gpu'
- link to Nvidia docs for installing the container runtime toolkit
- list docker v19.03 as minimum version, to track with nvidia's new container runtime toolkit
