db/storage.go
func (s *Storage) Users() *storage.Collection {
	emailIndex := mgo.Index{Key: []string{"email"}, Unique: true}
	c := s.Collection("users")
	c.EnsureIndex(emailIndex)
	return c
}
func (s *Storage) Users() *storage.Collection {
	emailIndex := mgo.Index{Key: []string{"email"}, Unique: true}
	c := s.Collection("users")
	c.EnsureIndex(emailIndex)
	return c
}
// Users returns the users collection from MongoDB.