Add accessibility performance

[jendiamond]

There are some accessibility issues with this gem. I am working on some fixes now but they aren't perfected yet. :)

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The date range slider form accessibility issues on our site

The form tag is not labelled but the slider is well identified and useable. I added an aria-labelledby to the partial _range_limit_pane in our site but I think it needs to be a bit different.

<div class="limit_content range_limit" aria-labelledby="range limit slider">

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Possible fixes

• Add a label https://www.w3.org/WAI/tutorials/forms/labels/

• Use this gem to add a label to the form WAIAble 1.0.0 released! Now you can make your Rails forms accessible.