Tests derived from axe-core test suite: https://github.com/dequelabs/axe-core/tree/develop/test.

Includes:
- `LICENSE`

Modified:
- `implicit-role.js` contains test cases extracted from `/test/commons/aria/implicit-role.js`
- `accessible-text.js` contains test cases extracted from `/test/commons/aria/accessible-text.js`
