Use new access token endpoints

Merge pull request #30 from waytohealth/WTH-5837

WTH-5837 update access/refresh token endpoints

Update client to work with newer oauth2-client version

Merge pull request #6 from waytohealth/change-exception-response

Change exception response

Locks oauth2-client version

Merge pull request #5 from waytohealth/lock-client-version

Lock version of oauth2 client to before they made a breaking change.

Initial release

Merge pull request #3 from lostfocus/master

Changed URL from Nokia to Withings