Add allennlp test-install command

[nelson-liu]

Fixes #856 by creating an allennlp test-install command that runs the unit test suite.

I've tested it locally outside of my allennlp install directory and it seems to work fine for both options, but unsure how to write a unit test for this.

This command skips the sniff tests by default, which should address @DeNeutoy 's concern from #1208 ?

[joelgrus]

I would pull out the project_root logic into a function and test that at least.

I would probably also store the initial working dir and change back to it at the end, not sure if it makes a difference, but it feels cleaner.

I can't think of a good way to test it either

[DeNeutoy]

Yeah, I don't think we can test the thing which runs the tests in the tests 😆

Once we set up CI which runs the pip installation, this will be tested implicitly by that, so I think we're all good.

[nelson-liu]

I realized that if the test_requirements (pytest, flaky, responses>=0.7, jupyter) are not installed, this will totally break all of the allennlp commands.

Is it worth adding these packages to the requirements installed by pip? Alternatively, we could fix #1200 ...

[matt-gardner]

The whole reason requirements.txt was separate from test_requirements.txt was because we weren't including the tests in the pip release. If we're going to include tests in the pip release, do we need that distinction anymore?

[nelson-liu]

perhaps we can move these essential testing packages (pytest, flaky, responses>=0.7, jupyter) to requirements.txt and the setup.py install_requires, then rename requirements_test.txt to requirements_dev.txt?

no need for a user to install sphinx or numpydoc or coverage...

[matt-gardner]

I think others have stronger / more informed opinions here than me, so I'll let someone else answer the question. I was just providing some context.

[schmmd]

Jupyter is enormous and is currently in our test_requirements (see #645). I'd rather not have that in our requirements.txt--but at the same time it'd be great to eliminate test_requirements so I'm not sure what's best!

[nelson-liu]

another option is to turn off notebook tests by default in test-install and make users install jupyter in order to run them. This means that jupyter can stay in test_requirements and doesn't have to be installed by default.

[joelgrus]

ANOTHER option is to rewrite the notebook tutorials as markdown tutorials and get rid of our jupyter dependency altogether 😇

[DeNeutoy]

@nelson-liu Either solution you propose is fine - we can re-write the tutorials in a separate PR