mbio ontology: update parent for age & age group

[danicahelb]

In mbio, age and age group are under different parents (see gems1 example)

in clinepi, age and age group are both under parent observation details (see gems1 example)

please update mbio ontology so that age falls under observation details instead of demographics

[SheenaTomko]

Note that we decided a few months ago to move "Age" to Demographics. The real change needed here is to move "Age group" to Demographics in all studies (ClinEpi and Mbio)

[jaycolin]

Patched in feature.microbiomedb.org so it will go out in b62

[SheenaTomko]

Nupur confirmed this looks good!