Add user to project by id or email and list of user who have access

Two features
1. Add user by id or email
```
logan = Logan::Client.new(....)

logan.projects.first.add_user_by_id(123456)
logan.projects.first.add_user_by_email('dummy@gmail.com')
```

2. Get list of users who have access to the project
```
# will return List of Person
logan.projects.first.accesses
```