spring security tokenStore keys.

redis token store key specs

access: 
accessToken-> OAuth2AccessToken

auth:
accessToken -> OAuth2Authentication

auth_to_access:
md5(OAuth2Authentication -> {username=xxx,client_id=xxx,scope=xxx}) -> OAuth2AccessToken

uname_to_access: Set
clientId +":"+ username(phone) -> OAuth2AccessToken

client_id_to_access: Set
clientId -> OAuth2AccessToken

refresh_to_access:
refreshToken -> OAuth2RefreshToken

access_to_refresh:
accessToken -> refreshToken