Store thumbnail url of rune, too

Signed-off-by: SeongJae Park <sj38.park@gmail.com>
Increase Exp a little when scanned

Increase Exp 1 when scanned a book

Signed-off-by: SeongJae Park <sj38.park@gmail.com>
Implement level-up

Exp for next level up is calculated by
`level * 100 + pow(8, level - 1)`.

Signed-off-by: SeongJae Park <sj38.park@gmail.com>
Calculate mp / scanCount heal properly

Former code has bug.

Signed-off-by: SeongJae Park <sj38.park@gmail.com>
Implement bonus point

User can increase their stat using bonus point.

Signed-off-by: SeongJae Park <sj38.park@gmail.com>
Implement POST /changestat

Signed-off-by: SeongJae Park <sj38.park@gmail.com>