Set capabilities of the persona store.
This sets the capabilities of the store, as if they were changed on a backing store somewhere. This is intended to be used for testing code which depends on the values of Folks.PersonaStore.can_add_personas, Folks.PersonaStore.can_alias_personas and Folks.PersonaStore.can_remove_personas.
| can_add_personas | whether the store can handle adding personas | 
| can_alias_personas | whether the store can handle and update user-specified persona aliases | 
| can_remove_personas | whether the store can handle removing personas | 
0.9.7