API - get roster

[Matt Bozwood-Davies]

Is there any chance we can get the join date returned in the API, in the same format that is shown on the facility members page? It would be a benefit to us for certain pages we have.

{"cid":"1240411","fname":"Matt","lname":"Bozwood-Davies","email":"[e-mail]","rating":"8"}

to become

{"cid":"1240411","fname":"Matt","lname":"Bozwood-Davies","email":"[e-mail]","rating":"8","join_date":"{value}"}

[Daniel Hawton]

Commit e77f121 will be live at the half