Refact tests
Change internal API
Refact main.go
Add Pluck
Support select
Add method to do basic check for sql valid or not
Make pluck works
Yay, order works
Yay, Limit works
Yay, Offset works
Refact where method
Yay, Or works
Remove method Not for less confuse
orm.Errors to hold all errors happened, orm.Error store the last error
yay, created_at, updated_at works
Add callbacks support
Yay, callbacks works
Add tests for callbacks