v0.9.0

• [change] Unify observer.query and observer.doc properties as observer.content #105
• [add] Expose name and functions in functions Callable #106
• [add] query.reload() #110
• [fix] nested reference parents (store.collection('ducks').doc('yellow/feathers/white')) #111
• [add] store.models helpers #112
• [add] api docs (1st draft) #102