Add revoke method

[marcomontalbano]

What I did

I added a revoke method.

Any previously generated access tokens (refresh tokens included) can be revoked before their natural expiration date.

import { revoke } from '@commercelayer/js-auth'

await revoke({
  clientId: 'your-client-id',
  clientSecret: 'your-client-secret',
  token: 'a-generated-access-token'
})

Checklist

• Make sure your changes are tested (stories and/or unit, integration, or end-to-end tests).
• Make sure to add/update documentation regarding your changes.
• You are NOT deprecating/removing a feature.