Added specs for Koala's errors.
Added specs for Koala's errors.

samnang/koala,hendricius/koala,arsduo/koala,lisa-lina/koala,christer155/koala,supriyantomaftuh/koala,Loke155/koala,morgoth/koala,lucaskds/koala,sideci-sample/sideci-sample-koala,chrisortman/koala,adparlor/koala,sancopanco/koala,mateusrevoredo/koala