Cannot currently write correct metadata from NRL v1 or v2: state of health channels

[rcasey-earthscope]

@metempleton : I could not currently write correct metadata (with either NRL version), due either to bugs or inappropriate logic, state of health channels (yasmine requires exactly one paz element; SOH needs none)

[rcasey-earthscope]

we should list some example SOH channels (full source ID) that represent these non-PAZ cases.

[metempleton]

This is bug #39