Add compatibility with matcher-combinators

[plexus]

Currently when running a test through cider, any failures in a
(is (match? ,,,)) clause will be silently ignores.

This detects mismatch messages and treats them as failure messages. Where there
is a mismatch the user will see a {:expected x :actual y} in the test output.

[plexus]

This is a logical follow-up to #510, where it was mentioned that matcher-combinators should use a namespaced keyword for its custom message type, which is does since nubank/matcher-combinators#34.

[bbatsov]

@plexus LGTM.

Can you please mention this in the changelog as well?

Maybe also add that bit of documentation that was discussed in #510 as well for future reference.

[codecov]

Codecov Report

Merging #546 into master will decrease coverage by 0.05%.
The diff coverage is 33.33%.

@@            Coverage Diff             @@
##           master     #546      +/-   ##
==========================================
- Coverage   73.07%   73.02%   -0.06%     
==========================================
  Files          36       36              
  Lines        2366     2369       +3     
  Branches      137      137              
==========================================
+ Hits         1729     1730       +1     
- Misses        500      502       +2     
  Partials      137      137

Impacted Files	Coverage Δ
src/cider/nrepl/middleware/test.clj	57.89% <33.33%> (-0.4%)	⬇️

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[plexus]

I've updated the CHANGELOG. Which documentation are you refering to @bbatsov? There's already a bit about extensibility in the docs. Or do you mean this exchange? I'm not sure what the conclusion from that is...

[bbatsov]

@plexus I was referring to:

@xiongtx I'm guessing we should add some integration notes in CIDER's manual, otherwise people are going to have a hard time figuring out what they are supposed to do.

(meaning documenting how to extend report, but that's not a big deal)