Make sure that negative matcher fails on multiple enqueues of the same kind

[povilasjurcys]

Fix for #1870.

Without this fix test passes for given example

expect {
  job.perform_later
  job.perform_later
}.not_to have_enqueued_job

This happens because by default we check using options :exactly, 1. That is, under the hood
}.not_to have_enqueued_job
is same as
.not_to have_enqueued_job.exactly(:once).

In negative examples this is incorrect - we should use :exaclty, 0 instead.
Negative example
.not_to have_enqueued_job
should be equal to positive example with conditions
.to have_enqueued_job.exactly(0)

[fables-tales]

can you provide full examples of what the various kinds of error messages look like when this matcher fails?

[povilasjurcys]

@samphippen did you had something like this in mind: 38801ac

[pirj]

This is pretty much covered in #2069
Please feel free to reopen if you're up to improve current failure messages.

In general, the use of quantitive qualifiers with negated version of those matchers reads weird.