how to run mocha tests on asynchronous functions in script
// async/await
it('responds with matching records', async function() {
const users = await db.find({ type: 'User' });
users.should.have.length(3);
});
// promise.then()
it('should save without error', function(done) {
var user = new User('Luna');
user.save(function(err) {
if (err) done(err);
else done();
});
});