Make trove classifiers accordion only open one tab at once

[dstufft]

Currently you can view more than one section of trove classifiers at one time, for example, both By Environment and By Framework could be open.

Given the potential length of the page, I think we should consider enforcing the closing of other sections when a new one is opened.

• Copied from Make trove classifiers accordion only open one tab at once nlhkabu/warehouse-ui#2*

[di]

I created a branch which fixes this here: dabbdfe...di:fix-755

However, in doing so I noticed that this would introduce an issue with the UI that we probably don't want: Because some of the classifier lists are longer than the viewport, if one of them, such as "By Programming Language", is open:

And we scroll to the bottom:

When we click "By Development Status", it disappears, because it's much shorter, and the entire list has jumped out of the viewport:

I suppose we could address that by additionally forcing a jump to an anchor tag on the category, but I feel like that would be worse UX than what we've got as-is.

@nlhkabu, thoughts?