Fix invalid appearance in Apros due to their box-sizing global

[bradenmacdonald]

Apros CSS has the rule *, *:before, *:after { box-sizing: border-box; }, which (not surprisingly) messes up the layout of our tip popups.

Before screenshot:

After screenshot:

Testing instructions:

• Use a birch rebase branch of the solutions fork of edx-platform. The only one that's currently working for me is braden/birch-rebase-testing

• Add the following to ~/lms.env.json:

    "XBLOCK_SETTINGS": {
        "mentoring": {
            "theme": {
                "package": "problem_builder",
                "locations": ["public/themes/apros.css"]
            }
        }
    }

• Open Apros and look at an MCQ/MRQ with tips.

[e-kolpakov]

@bradenmacdonald 👍 - not verified for the same reason I gave at jquery-xblock PR

[antoviaque]

@bradenmacdonald Thanks for fixing this!

The screenshots made me notice that the checkmarks/exclamation marks aren't well aligned - if you look closely their center is below the center of the corresponding line. (It's also worth checking with answers that have multiple lines btw, or contain HTML, as we've had issues with those in the past)

[Kelketek]

@bradenmacdonald I would have given you a +1, but since @antoviaque appears to have added a bit here, so I'm going to hold off until that's all groovy.

[bradenmacdonald]

OK, should be fixed in latest commit. How's this?

Apros screenshot:

Studio screenshot:

[antoviaque]

@bradenmacdonald That looks great : ) Thanks for the fix!

[Kelketek]

@bradenmacdonald I'm going to work on getting a rebased solutions devstack up and running. However I'd like you to see if you can fix the flaky test that failed the push build on Travis in the meantime.

[bradenmacdonald]

@Kelketek Sure thing. I have now fixed the flaky test in this PR (I hope). Turns out I was using a random number that was not sufficiently random, resulting in conflicting ids for label/checkbox pairs.

[e-kolpakov]

@bradenmacdonald verified, this PR looks good, but it missed the fixes you made in #9. Conditional 👍 if #9 is to be added later.

[bradenmacdonald]

Thanks @e-kolpakov. Yes, Once #9 is approved and merged I will cherry-pick all of its fixes onto master as well.

[Kelketek]

LGTM 👍