Enhance the testing of mitls for the everest nightly upgrade job

[msprotz]

• The purpose of everest nightly upgrade is to pull the latest master of each project, check that everything "works together", then commit and push.
• Right now, the definition of "works together" is: "build, then mitls.exe -v 1.2 www.google.com 443" works.

Task description.

• First sub-task. "Works together" should include "verifies."
  • create a "verify" action for the everest script that launches the verification of mitls (the right invocation can be found under the mitls-ci target of the ci script)
  • make the ci script call everest verify in addition to build and test
• Second sub-task. The call to mitls.exe is suboptimal. It should use -tlsapi, but then we get a not found error.
  • From Antoine:

    as for your 404 error on test it's because the request on -tlsapi is not for /
    you can change the payload in test/TestAPI.fst
    may be worth putting as a config option for mitls.exe

  • Then, figure out why the test ends up with ReadError: TCP close; if this is an actual error, the return code should be non-zero. If it's not, it shouldn't say error.

[msprotz]

I did the first sub-task.

[msprotz]

@fournet can you at least comment on how we could improve the testing of mitls.exe? https://github.com/project-everest/everest/blob/master/everest#L833 this is what we run, which in turn is https://github.com/mitls/mitls-fstar/blob/master/src/tls/Extracted.mk#L120 -- maybe run more interop, post a report in the logs, something...?