as it is part of the Urchin background where the purpose would be to avoid starvation, ie. a homeless child hiding away their own rations from scraps they gather, though I haven't actually attempted or thought of using them yet. It's been mostly for the fun of RP. ...
The last UA proposed a subclass of the Warlock where the patron is a celestial: http://media.wizards.com/2017/dnd/downloads/June5UA_RevisedClassOptv1.pdf Non-fiend patrons don't have to be evil. There can be good ones who probably want your warlock to do something heroic or vanquis...