`.toBeObject` passes with `null`

[JuanGalilea]

yeah yeah i know null is typeof 'object' but idc.

Nobody relies on that and 99% of the time someone writes .toBeObject the mean it to be an actual object. Otherwise we wouldn't have the Array.isArray clause in there.

PS: Also a thing like .toBeNil would be nice

I can implement it but not today.

WDYT @ruocco-l ?