fix(core): Explicitly name the axe module 'axe-core'

[noead01]

Avoid the "Mismatched anonymous define() modules" error when the axe script is injected in a page that uses requireJS

Closes #849

PR Checklist

Please check if your PR fulfills the following requirements:

• The commit message(s) follow our guidelines: https://github.com/dequelabs/axe-core/blob/develop/doc/code-submission-guidelines.md#git-commits
• Changes to rules and checks appropriately support Shadow DOM
• Changes have been tested in major browsers and Assistive Technologies
• Tests for the changes have been added (for bug fixes / features)
• Docs have been added / updated (for bug fixes / features)

Description of the changes

• Github issue: 849

Does this PR introduce a breaking change?

[ ] Yes
[x] No

Other information

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[noead01]

Issues with my github setup on ubuntu. Closing this PR and submitting yet another one with all correct info to satisfy the CLA