Feature Request: Implement Refresh token mechanism

[DasJott]

In your code you retrieve the token using the client_credentials grant. You also suggest to store that token for later use, which is very good.
In case that stored token once dies, there is a refresh token you can use to get a new token easily. That is OAuth2 standard. Maybe you could implement something to help people accomplish that? Of course it depends on how the token was stored...

I could think of many people not storing the token and creating a new on each API call...
Also: you would never have to care about the token anymore, as that refresh process can run automated.

For any help on that topic, see the official cleverreach documentation