Steps to reproduce (assumes ChromeVox or similar)

1. Open https://elastic.github.io/eui/#/layout/accordion in a new tab.
2. Tab through to the "Accordion for forms" section and tab to the first accordion
3. Open the accordion
4. Tab to the X button

Actual Result

"Delete Button"

Expected Result

"Close Accordion" or some such thing

Category: #720 : Elastic UI Accordions Accessibility
Relevant WCAG Criteria: [3.3.2 Input Assistance: Labels or Instructions(https://www.w3.org/WAI/WCAG20/quickref/#qr-minimize-error-cues)