EDM-less continuous integration

[mdickinson]

EDIT: Currently blocked by #1205 (which is fixed in #1206).

This PR updates the continuous integration to avoid using etstool.py and EDM.

Closes #687

Main advantages:

• much simpler
• supports running tests on Python 3.5, Python 3.7, Python 3.8 and Python 3.9-dev
• supports testing on 32-bit Windows
• easy notifications of breakage due to external package updates

Disadvantages

• without pinned dependent package versions, we can't control timing of breakage due to an external package being updated
• not easy to test multiple Python versions on macOS
• as currently written, this only runs tests against a local dev install, not against a proper install; errors due to missing package_data won't be detected. This could be fixed.

Still to do:

• get Travis CI build actually working
• extend to Appveyor
• remove the EDM installation support scripts
• restore docs build
• run tests more carefully (against a proper install, not a dev install, and from a temporary directory)
• run mypy tests

[mdickinson]

This was just a proof of concept, and @corranwebster has a more complete solution in the works. Closing.

[mdickinson]

This is now ready for review.

Note that we only test one version of Python on macOS; testing multiple versions of Python on macOS seems to be hard to do. (Using brew doesn't help, since unlike MacPorts, it doesn't support multiple different Python 3 versions.)

Given that we have good coverage of Python versions on Linux (3.5 through 3.9), I think that's good enough.

[mdickinson]

This needs a master merge for the traits-stubs setup changes; I'm expecting the CI to break after that merge because of missing mypy in the test environment.

Will merge (master into this branch), then observe and fix the breakage.

[mdickinson]

Well, that's not the failure I was expecting:

======================================================================
ERROR: test_abbreviated_annotations (traits.util.tests.test_trait_documenter.TestTraitDocumenter)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "C:\Python37\lib\site-packages\traits\util\tests\test_trait_documenter.py", line 119, in test_abbreviated_annotations
    documenter.generate(all_members=True)
  File "C:\Python37\lib\site-packages\sphinx\ext\autodoc\__init__.py", line 771, in generate
    if not self.parse_name():
  File "C:\Python37\lib\site-packages\sphinx\ext\autodoc\__init__.py", line 326, in parse_name
    with mock(self.env.config.autodoc_mock_imports):
  File "C:\Python37\lib\site-packages\sphinx\config.py", line 250, in __getattr__
    raise AttributeError(__('No such config value: %s') % name)
AttributeError: No such config value: autodoc_mock_imports
----------------------------------------------------------------------

Looks like a new version of Sphinx was released recently, and it breaks the trait-documenter. I've opened #1205 to track this.

[kitchoi]

Mostly LGTM. One question and etstool.py install is failing on this branch...

[kitchoi]

etstool.py install fails because this file is removed. We probably need to keep this for now or etstool.py will need to be updated accordingly. Probably easiest to keep this file and worry about the future of etstool.py separately.

[mdickinson]

Thanks. I've added it back.

[mdickinson]

Hmm. We shouldn't actually need enthought/lgpl or enthought/gpl here, but as you say, this can be changed in a separate PR.

[kitchoi]

LGTM

[mdickinson]

Thanks for reviewing!