Remove yaml_db dependency

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>
Update rails

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>
Bump version

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>
Improve setup instructions

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>