Incorrect storage key for access token in signOut method

[E-Kuerschner]

Library version: 3.1.4

Offending line:

okta-auth-js/packages/okta-auth-js/lib/browser/browser.js

Line 296 in 75d5a72

accessToken = await sdk.tokenManager.get('token');

In literally every other piece of documentation online the access token is shown being stored under the key "accessToken". What this means is if a dev is following the official Okta guides (as one would assume they would do) then the revokeAccessToken feature will work incorrectly.

[swiftone]

@E-Kuerschner - Good catch, the definitely looks wrong. We'll fix and add tests.

Internal Ref: OKTA-315806

[shuowu]

Link the fix PR here: #436
Pending for release.