Make docs about expect_next_instance_of consistent
Make docs about expect_next_instance_of consistent

So we compare `expect_any_instance_of` with
`expect_next_instance_of`, but still mention
`allow_any_instance_of`.

dreampet/gitlab,dreampet/gitlab,iiet/iiet-git,stoplightio/gitlabhq,axilleas/gitlabhq,axilleas/gitlabhq,iiet/iiet-git,iiet/iiet-git,dreampet/gitlab,stoplightio/gitlabhq,mmkassem/gitlabhq,mmkassem/gitlabhq,axilleas/gitlabhq,mmkassem/gitlabhq,stoplightio/gitlabhq,axilleas/gitlabhq,iiet/iiet-git,dreampet/gitlab,stoplightio/gitlabhq,mmkassem/gitlabhq