Integrate accuracy test into CI

[liushuyu]

In this PR, HW LLE accuracy test is included in CI checks.

Currently, due to a bug in Travis CI Windows agent, the test on that platform is disabled.

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And I think there will be some work to do if you want to use Catch2 Unit Test Framework. It does not provide "skip" method, and you need to sub-class the Matcher to make it outputs the useful information.

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This change is 

[wwylele]

Here are some problems I found:

• You said on discord that the uploaded file is temporary and the data is kept alive by CI's cache. But cache can be removed in many cases like:
  • I mess up something and have to clean everything
  • Travis messes up their stuff and have to clean everything Do I have to reupload the file every time cache is removed?
• Could you also add the test to appveyor as well?
• test_verifier currently doesn't return error code in case of test failure
• does ctest output what test_verifier prints (at least on failure)? It would be nice to know which test case fails exactly.

[liushuyu]

Do I have to reupload the file every time cache is removed?

No, as you can see in CMakeLists.txt, I uploaded the file to a paid CDN service. They won't remove the file of course. I used the cache system in CI services because:

1. Usually, their cache storage server is faster to be accessed in their containers
2. To reduce my own cost

Could you also add the test to appveyor as well?

I will address this.

test_verifier currently doesn't return error code in case of test failure

That's fine, I can modify that small program to return a non-zero status if more than zero test fails.

does ctest output what test_verifier prints (at least on failure)? It would be nice to know which test case fails exactly.

Yes but only if test_verifier returns a non-zero status.

[liushuyu]

Issues addressed.