DRY Jackson mapper configuration with JsonMapperFactory
Change date formatting in JSON to ISO 8601
check-token: change param name to 'token' and allow GET only (API change!)

Parameter 'access_token' is used for OAuth authentication itself,
so this was ambiguous.
Change /api/check-token to /api/v1/tokeninfo (API change!)
Change scopes prefix from urn:ctu to urn:zuul
Add TokenInfo API specification