Null property values in event callbacks

[appy-one]

When creating nodes that have properties with null values, events are triggered with the same objects, including the null property values.

Example:

const ref = db.ref('users')
ref.on('child_added', snap => {
    const user = snap.val();
    console.log(user.address); // null (expected: undefined)
});
ref.push({ name: 'Ewout', address: null });

null valued properties should be stripped from the objects for event callbacks

[appy-one]

Fixed in v1.0.2