Suppress warnings about pytest trying to collect TestProject

[YannickJadoul]

Fixes #372

We (probably) need to use this __test__ = False attribute, because it's from .test_projects import TestProject that causes the warning. The test_projects subfolder is not the issue, since base.py does not have the test_ prefix.

Alternatively, we could have a new_base_project function, similar to new_c_project?

[YannickJadoul]

@joerick The warnings are gone, so if this 4a335f4 fixes the unrelated Travis CI-Python 3.6-SSL error, this is ready for review (?) and merging.

[YannickJadoul]

So Travis CI still fails, even with the 62f88a2 commit (amended 4a335f4, where I had forgotten to change C:\Python36 into C:\Python37). Let's hope Travis fixes this, and roll back that second commit?

[YannickJadoul]

@mayeut Since you keep on providing us with SSL patches for macOS, do you know anything about issues on Windows with SSL? Travis CI apparently uses Windows Server 1809, so maybe something is too old there?

This seems to be relevant, but I cannot get it to work on Travis: https://bugs.python.org/issue36011

[mayeut]

@YannickJadoul,
the issue on Windows seems indeed to be the one you linked to.
It's unrelated to why a patch was needed on macOS for CPython 3.4/3.5 and I was unaware of the Windows one.

The method from http://www.chawn.com/RootCerts.htm should work. (also for reference, http://woshub.com/updating-trusted-root-certificates-in-windows-10/)

[YannickJadoul]

Amazing! That works!
Thank you very much, @mayeut! Would have taken me a lot longer to figure out :-)