Adjust elements to fix JSX-A11Y accessibility warnings

[kellyi]

Overview

#62 upgrades ESLint and eslint-jsx-a11y to newer versions. The newer version of eslint-jsx-a11y revealed some problems with how the previous DOM elements were set up.

For #62 I added eslint-disable declarations to the files which had accessibility linter warnings. We need to fix these by using the proper elements.

Expected Behavior

App producers no warnings from the accessibility linter -- and the linter is not disabled in any way.

Actual Behavior

App produces some warnings from the accessibility linter -- and the linter is currently disabled for a few rules in a few files.