Example collector and analyzer spec using URI for updates

[xavpaice]

Request

The work in #694 adds the ability and documentation for a URI field to be used for updating specs.

This request is to create an example of that usage, exercising the feature. Suggested is a collector and analyzer that searches for the ekco version, and warns if it's out of date or if it there's a known error with the version installed (e.g. lack of certificate rotation).

In scope

• Add one yaml file to the https://github.com/replicatedhq/troubleshoot-specs/ repo which contains the appropriate collector and analyzer for ecko versions, plus a uri pointing to the doc in Github
• The yaml itself must contain enough detail that it can run standalone without needing to go to the URI.

Definition of done

• [ ] New spec is written and merged to https://github.com/replicatedhq/troubleshoot-specs/
• [ ] A post on https://community.replicated.com/ explaining how this can be used from the CLI, and referencing the docs created in #694